automated code clean up

src/conversations/java/eu/siacs/conversations/entities/AccountConfiguration.java

@@ -1,7 +1,6 @@
 package eu.siacs.conversations.entities;
 
 import com.google.common.base.Preconditions;
-import com.google.common.base.Strings;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonSyntaxException;

src/conversations/java/eu/siacs/conversations/services/ImportBackupService.java

@@ -12,9 +12,10 @@ import android.net.Uri;
 import android.os.Binder;
 import android.os.IBinder;
 import android.provider.OpenableColumns;
+import android.util.Log;
+
 import androidx.core.app.NotificationCompat;
 import androidx.core.app.NotificationManagerCompat;
-import android.util.Log;
 
 import com.google.common.base.Charsets;
 import com.google.common.base.Stopwatch;
@@ -60,7 +61,7 @@ import eu.siacs.conversations.xmpp.Jid;
 public class ImportBackupService extends Service {
 
     private static final int NOTIFICATION_ID = 21;
-    private static AtomicBoolean running = new AtomicBoolean(false);
+    private static final AtomicBoolean running = new AtomicBoolean(false);
     private final ImportBackupServiceBinder binder = new ImportBackupServiceBinder();
     private final SerialSingleThreadExecutor executor = new SerialSingleThreadExecutor(getClass().getSimpleName());
     private final Set<OnBackupProcessed> mOnBackupProcessedListeners = Collections.newSetFromMap(new WeakHashMap<>());

src/conversations/java/eu/siacs/conversations/ui/EasyOnboardingInviteActivity.java

@@ -2,17 +2,17 @@ package eu.siacs.conversations.ui;
 
 import android.app.Activity;
 import android.content.Intent;
-import androidx.databinding.DataBindingUtil;
 import android.graphics.Bitmap;
 import android.graphics.Point;
 import android.os.Bundle;
-import androidx.appcompat.widget.Toolbar;
 import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.widget.Toast;
 
+import androidx.databinding.DataBindingUtil;
+
 import com.google.common.base.Strings;
 
 import eu.siacs.conversations.Config;
@@ -34,7 +34,7 @@ public class EasyOnboardingInviteActivity extends XmppActivity implements EasyOn
     public void onCreate(final Bundle bundle) {
         super.onCreate(bundle);
         this.binding = DataBindingUtil.setContentView(this, R.layout.activity_easy_invite);
-        setSupportActionBar((Toolbar) binding.toolbar);
+        setSupportActionBar(binding.toolbar);
         configureActionBar(getSupportActionBar(), true);
         this.binding.shareButton.setOnClickListener(v -> share());
         if (bundle != null && bundle.containsKey("invite")) {

src/conversations/java/eu/siacs/conversations/ui/ImportBackupActivity.java

@@ -5,21 +5,22 @@ import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.ServiceConnection;
-import androidx.databinding.DataBindingUtil;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.IBinder;
-import com.google.android.material.snackbar.Snackbar;
-import androidx.core.content.ContextCompat;
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.widget.Toolbar;
 import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 
+import androidx.appcompat.app.AlertDialog;
+import androidx.core.content.ContextCompat;
+import androidx.databinding.DataBindingUtil;
+
+import com.google.android.material.snackbar.Snackbar;
+
 import java.io.IOException;
 import java.util.List;
 
@@ -48,7 +49,7 @@ public class ImportBackupActivity extends ActionBarActivity implements ServiceCo
         setTheme(this.mTheme);
         super.onCreate(savedInstanceState);
         binding = DataBindingUtil.setContentView(this, R.layout.activity_import_backup);
-        setSupportActionBar((Toolbar) binding.toolbar);
+        setSupportActionBar(binding.toolbar);
         setLoadingState(savedInstanceState != null && savedInstanceState.getBoolean("loading_state", false));
         this.backupFileAdapter = new BackupFileAdapter();
         this.binding.list.setAdapter(this.backupFileAdapter);

src/conversations/java/eu/siacs/conversations/ui/MagicCreateActivity.java

@@ -2,14 +2,14 @@ package eu.siacs.conversations.ui;
 
 import android.content.Intent;
 import android.content.pm.ActivityInfo;
-import androidx.databinding.DataBindingUtil;
 import android.os.Bundle;
-import androidx.appcompat.widget.Toolbar;
 import android.text.Editable;
 import android.text.TextWatcher;
 import android.view.View;
 import android.widget.Toast;
 
+import androidx.databinding.DataBindingUtil;
+
 import java.security.SecureRandom;
 
 import eu.siacs.conversations.Config;
@@ -61,7 +61,7 @@ public class MagicCreateActivity extends XmppActivity implements TextWatcher {
         }
         super.onCreate(savedInstanceState);
         this.binding = DataBindingUtil.setContentView(this, R.layout.magic_create);
-        setSupportActionBar((Toolbar) this.binding.toolbar);
+        setSupportActionBar(this.binding.toolbar);
         configureActionBar(getSupportActionBar(), this.domain == null);
         if (username != null && domain != null) {
             binding.title.setText(R.string.your_server_invitation);

src/conversations/java/eu/siacs/conversations/ui/ManageAccountActivity.java

@@ -5,9 +5,6 @@ import android.content.Intent;
 import android.os.Bundle;
 import android.security.KeyChain;
 import android.security.KeyChainAliasCallback;
-import androidx.annotation.NonNull;
-import androidx.appcompat.app.ActionBar;
-import androidx.appcompat.app.AlertDialog;
 import android.util.Pair;
 import android.view.ContextMenu;
 import android.view.ContextMenu.ContextMenuInfo;
@@ -18,6 +15,10 @@ import android.widget.AdapterView.AdapterContextMenuInfo;
 import android.widget.ListView;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.ActionBar;
+import androidx.appcompat.app.AlertDialog;
+
 import org.openintents.openpgp.util.OpenPgpApi;
 
 import java.util.ArrayList;
@@ -31,8 +32,8 @@ import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.services.XmppConnectionService.OnAccountUpdate;
 import eu.siacs.conversations.ui.adapter.AccountAdapter;
 import eu.siacs.conversations.ui.util.MenuDoubleTabUtil;
-import eu.siacs.conversations.xmpp.XmppConnection;
 import eu.siacs.conversations.xmpp.Jid;
+import eu.siacs.conversations.xmpp.XmppConnection;
 
 import static eu.siacs.conversations.utils.PermissionUtils.allGranted;
 import static eu.siacs.conversations.utils.PermissionUtils.writeGranted;
@@ -226,7 +227,7 @@ public class ManageAccountActivity extends XmppActivity implements OnAccountUpda
 
 
     @Override
-    public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
         if (grantResults.length > 0) {
             if (allGranted(grantResults)) {
                 switch (requestCode) {

src/conversations/java/eu/siacs/conversations/ui/PickServerActivity.java

@@ -2,12 +2,12 @@ package eu.siacs.conversations.ui;
 
 import android.content.Intent;
 import android.content.pm.ActivityInfo;
-import androidx.databinding.DataBindingUtil;
 import android.os.Bundle;
-import androidx.appcompat.app.AppCompatActivity;
-import androidx.appcompat.widget.Toolbar;
 import android.view.MenuItem;
 
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.databinding.DataBindingUtil;
+
 import java.util.List;
 
 import eu.siacs.conversations.R;
@@ -66,7 +66,7 @@ public class PickServerActivity extends XmppActivity {
         }
         super.onCreate(savedInstanceState);
         ActivityPickServerBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_pick_server);
-        setSupportActionBar((Toolbar) binding.toolbar);
+        setSupportActionBar(binding.toolbar);
         configureActionBar(getSupportActionBar());
         binding.useCim.setOnClickListener(v -> {
             final Intent intent = new Intent(this, MagicCreateActivity.class);

src/conversations/java/eu/siacs/conversations/ui/WelcomeActivity.java

@@ -4,20 +4,19 @@ import android.Manifest;
 import android.content.ActivityNotFoundException;
 import android.content.Intent;
 import android.content.pm.ActivityInfo;
-
-import androidx.databinding.DataBindingUtil;
 import android.net.Uri;
 import android.os.Bundle;
 import android.security.KeyChain;
 import android.security.KeyChainAliasCallback;
-import androidx.annotation.NonNull;
-import androidx.appcompat.app.AppCompatActivity;
-import androidx.appcompat.widget.Toolbar;
 import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.databinding.DataBindingUtil;
+
 import java.util.Arrays;
 import java.util.List;
 
@@ -120,7 +119,7 @@ public class WelcomeActivity extends XmppActivity implements XmppConnectionServi
         }
         super.onCreate(savedInstanceState);
         ActivityWelcomeBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_welcome);
-        setSupportActionBar((Toolbar) binding.toolbar);
+        setSupportActionBar(binding.toolbar);
         configureActionBar(getSupportActionBar(), false);
         binding.registerNewAccount.setOnClickListener(v -> {
             final Intent intent = new Intent(this, PickServerActivity.class);

src/conversations/java/eu/siacs/conversations/ui/adapter/BackupFileAdapter.java

@@ -1,13 +1,10 @@
 package eu.siacs.conversations.ui.adapter;
 
 import android.content.res.Resources;
-import androidx.databinding.DataBindingUtil;
 import android.graphics.Bitmap;
 import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
 import android.os.AsyncTask;
-import androidx.annotation.NonNull;
-import androidx.recyclerview.widget.RecyclerView;
 import android.text.format.DateUtils;
 import android.util.DisplayMetrics;
 import android.view.LayoutInflater;
@@ -15,6 +12,10 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ImageView;
 
+import androidx.annotation.NonNull;
+import androidx.databinding.DataBindingUtil;
+import androidx.recyclerview.widget.RecyclerView;
+
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.List;

src/main/java/eu/siacs/conversations/Config.java

@@ -6,8 +6,8 @@ import android.net.Uri;
 import java.util.Collections;
 import java.util.List;
 
-import eu.siacs.conversations.xmpp.chatstate.ChatState;
 import eu.siacs.conversations.xmpp.Jid;
+import eu.siacs.conversations.xmpp.chatstate.ChatState;
 
 public final class Config {
     private static final int UNENCRYPTED = 1;

src/main/java/eu/siacs/conversations/crypto/PgpEngine.java

@@ -2,9 +2,10 @@ package eu.siacs.conversations.crypto;
 
 import android.app.PendingIntent;
 import android.content.Intent;
-import androidx.annotation.StringRes;
 import android.util.Log;
 
+import androidx.annotation.StringRes;
+
 import org.openintents.openpgp.OpenPgpError;
 import org.openintents.openpgp.OpenPgpSignatureResult;
 import org.openintents.openpgp.util.OpenPgpApi;
@@ -30,8 +31,8 @@ import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.ui.UiCallback;
 
 public class PgpEngine {
-	private OpenPgpApi api;
+	private final OpenPgpApi api;
-	private XmppConnectionService mXmppConnectionService;
+	private final XmppConnectionService mXmppConnectionService;
 
 	public PgpEngine(OpenPgpApi api, XmppConnectionService service) {
 		this.api = api;

src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java

@@ -2,18 +2,19 @@ package eu.siacs.conversations.crypto.axolotl;
 
 import android.os.Bundle;
 import android.security.KeyChain;
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
 import android.util.Log;
 import android.util.Pair;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
-import org.whispersystems.libsignal.SignalProtocolAddress;
 import org.whispersystems.libsignal.IdentityKey;
 import org.whispersystems.libsignal.IdentityKeyPair;
 import org.whispersystems.libsignal.InvalidKeyException;
 import org.whispersystems.libsignal.InvalidKeyIdException;
 import org.whispersystems.libsignal.SessionBuilder;
+import org.whispersystems.libsignal.SignalProtocolAddress;
 import org.whispersystems.libsignal.UntrustedIdentityException;
 import org.whispersystems.libsignal.ecc.ECPublicKey;
 import org.whispersystems.libsignal.state.PreKeyBundle;
@@ -48,12 +49,12 @@ import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.utils.CryptoHelper;
 import eu.siacs.conversations.utils.SerialSingleThreadExecutor;
 import eu.siacs.conversations.xml.Element;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.OnAdvancedStreamFeaturesLoaded;
 import eu.siacs.conversations.xmpp.OnIqPacketReceived;
 import eu.siacs.conversations.xmpp.pep.PublishOptions;
 import eu.siacs.conversations.xmpp.stanzas.IqPacket;
 import eu.siacs.conversations.xmpp.stanzas.MessagePacket;
-import eu.siacs.conversations.xmpp.Jid;
 
 public class AxolotlService implements OnAdvancedStreamFeaturesLoaded {
 
@@ -85,9 +86,9 @@ public class AxolotlService implements OnAdvancedStreamFeaturesLoaded {
     private int numPublishTriesOnEmptyPep = 0;
     private boolean pepBroken = false;
     private int lastDeviceListNotificationHash = 0;
-    private Set<XmppAxolotlSession> postponedSessions = new HashSet<>(); //sessions stored here will receive after mam catchup treatment
+    private final Set<XmppAxolotlSession> postponedSessions = new HashSet<>(); //sessions stored here will receive after mam catchup treatment
-    private Set<SignalProtocolAddress> postponedHealing = new HashSet<>(); //addresses stored here will need a healing notification after mam catchup
+    private final Set<SignalProtocolAddress> postponedHealing = new HashSet<>(); //addresses stored here will need a healing notification after mam catchup
-    private AtomicBoolean changeAccessMode = new AtomicBoolean(false);
+    private final AtomicBoolean changeAccessMode = new AtomicBoolean(false);
 
     public AxolotlService(Account account, XmppConnectionService connectionService) {
         if (account == null || connectionService == null) {

src/main/java/eu/siacs/conversations/crypto/axolotl/SQLiteAxolotlStore.java

@@ -3,15 +3,15 @@ package eu.siacs.conversations.crypto.axolotl;
 import android.util.Log;
 import android.util.LruCache;
 
-import org.whispersystems.libsignal.SignalProtocolAddress;
 import org.whispersystems.libsignal.IdentityKey;
 import org.whispersystems.libsignal.IdentityKeyPair;
 import org.whispersystems.libsignal.InvalidKeyIdException;
+import org.whispersystems.libsignal.SignalProtocolAddress;
 import org.whispersystems.libsignal.ecc.Curve;
 import org.whispersystems.libsignal.ecc.ECKeyPair;
-import org.whispersystems.libsignal.state.SignalProtocolStore;
 import org.whispersystems.libsignal.state.PreKeyRecord;
 import org.whispersystems.libsignal.state.SessionRecord;
+import org.whispersystems.libsignal.state.SignalProtocolStore;
 import org.whispersystems.libsignal.state.SignedPreKeyRecord;
 import org.whispersystems.libsignal.util.KeyHelper;
 

src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlSession.java

@@ -1,10 +1,10 @@
 package eu.siacs.conversations.crypto.axolotl;
 
+import android.util.Log;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
-import android.util.Log;
 
-import org.whispersystems.libsignal.SignalProtocolAddress;
 import org.whispersystems.libsignal.DuplicateMessageException;
 import org.whispersystems.libsignal.IdentityKey;
 import org.whispersystems.libsignal.InvalidKeyException;
@@ -14,6 +14,7 @@ import org.whispersystems.libsignal.InvalidVersionException;
 import org.whispersystems.libsignal.LegacyMessageException;
 import org.whispersystems.libsignal.NoSessionException;
 import org.whispersystems.libsignal.SessionCipher;
+import org.whispersystems.libsignal.SignalProtocolAddress;
 import org.whispersystems.libsignal.UntrustedIdentityException;
 import org.whispersystems.libsignal.protocol.CiphertextMessage;
 import org.whispersystems.libsignal.protocol.PreKeySignalMessage;

src/main/java/eu/siacs/conversations/entities/Account.java

@@ -27,9 +27,9 @@ import eu.siacs.conversations.services.AvatarService;
 import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.utils.UIHelper;
 import eu.siacs.conversations.utils.XmppUri;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.XmppConnection;
 import eu.siacs.conversations.xmpp.jingle.RtpCapability;
-import eu.siacs.conversations.xmpp.Jid;
 
 public class Account extends AbstractEntity implements AvatarService.Avatarable {
 

src/main/java/eu/siacs/conversations/entities/Bookmark.java

@@ -1,6 +1,7 @@
 package eu.siacs.conversations.entities;
 
 import android.content.Context;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
@@ -21,7 +22,7 @@ import eu.siacs.conversations.xmpp.Jid;
 
 public class Bookmark extends Element implements ListItem {
 
-	private Account account;
+	private final Account account;
 	private WeakReference<Conversation> conversation;
 	private Jid jid;
 

src/main/java/eu/siacs/conversations/entities/Contact.java

@@ -4,9 +4,10 @@ import android.content.ContentValues;
 import android.content.Context;
 import android.database.Cursor;
 import android.net.Uri;
-import androidx.annotation.NonNull;
 import android.text.TextUtils;
 
+import androidx.annotation.NonNull;
+
 import com.google.common.base.Strings;
 
 import org.json.JSONArray;
@@ -28,9 +29,9 @@ import eu.siacs.conversations.services.QuickConversationsService;
 import eu.siacs.conversations.utils.JidHelper;
 import eu.siacs.conversations.utils.UIHelper;
 import eu.siacs.conversations.xml.Element;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.jingle.RtpCapability;
 import eu.siacs.conversations.xmpp.pep.Avatar;
-import eu.siacs.conversations.xmpp.Jid;
 
 public class Contact implements ListItem, Blockable {
     public static final String TABLENAME = "contacts";

src/main/java/eu/siacs/conversations/entities/Conversation.java

@@ -2,9 +2,10 @@ package eu.siacs.conversations.entities;
 
 import android.content.ContentValues;
 import android.database.Cursor;
+import android.text.TextUtils;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
-import android.text.TextUtils;
 
 import com.google.common.collect.ComparisonChain;
 import com.google.common.collect.Lists;
@@ -28,9 +29,9 @@ import eu.siacs.conversations.services.AvatarService;
 import eu.siacs.conversations.services.QuickConversationsService;
 import eu.siacs.conversations.utils.JidHelper;
 import eu.siacs.conversations.utils.UIHelper;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.chatstate.ChatState;
 import eu.siacs.conversations.xmpp.mam.MamReference;
-import eu.siacs.conversations.xmpp.Jid;
 
 import static eu.siacs.conversations.entities.Bookmark.printableValue;
 
@@ -68,12 +69,12 @@ public class Conversation extends AbstractEntity implements Blockable, Comparabl
     public AtomicBoolean messagesLoaded = new AtomicBoolean(true);
     protected Account account = null;
     private String draftMessage;
-    private String name;
+    private final String name;
-    private String contactUuid;
+    private final String contactUuid;
-    private String accountUuid;
+    private final String accountUuid;
     private Jid contactJid;
     private int status;
-    private long created;
+    private final long created;
     private int mode;
     private JSONObject attributes;
     private Jid nextCounterpart;
@@ -487,7 +488,7 @@ public class Conversation extends AbstractEntity implements Blockable, Comparabl
 
     public void setLastClearHistory(long time, String reference) {
         if (reference != null) {
-            setAttribute(ATTRIBUTE_LAST_CLEAR_HISTORY, String.valueOf(time) + ":" + reference);
+            setAttribute(ATTRIBUTE_LAST_CLEAR_HISTORY, time + ":" + reference);
         } else {
             setAttribute(ATTRIBUTE_LAST_CLEAR_HISTORY, time);
         }

src/main/java/eu/siacs/conversations/entities/MucOptions.java

@@ -1,8 +1,9 @@
 package eu.siacs.conversations.entities;
 
+import android.text.TextUtils;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
-import android.text.TextUtils;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -17,11 +18,11 @@ import eu.siacs.conversations.services.AvatarService;
 import eu.siacs.conversations.services.MessageArchiveService;
 import eu.siacs.conversations.utils.JidHelper;
 import eu.siacs.conversations.utils.UIHelper;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.chatstate.ChatState;
 import eu.siacs.conversations.xmpp.forms.Data;
 import eu.siacs.conversations.xmpp.forms.Field;
 import eu.siacs.conversations.xmpp.pep.Avatar;
-import eu.siacs.conversations.xmpp.Jid;
 
 public class MucOptions {
 
@@ -633,8 +634,8 @@ public class MucOptions {
         OUTCAST(0, R.string.outcast),
         NONE(1, R.string.no_affiliation);
 
-        private int resId;
+        private final int resId;
-        private int rank;
+        private final int rank;
 
         Affiliation(int rank, int resId) {
             this.resId = resId;
@@ -676,8 +677,8 @@ public class MucOptions {
         PARTICIPANT(R.string.participant, 2),
         NONE(R.string.no_role, 0);
 
-        private int resId;
+        private final int resId;
-        private int rank;
+        private final int rank;
 
         Role(int resId, int rank) {
             this.resId = resId;
@@ -744,7 +745,7 @@ public class MucOptions {
         private Jid fullJid;
         private long pgpKeyId = 0;
         private Avatar avatar;
-        private MucOptions options;
+        private final MucOptions options;
         private ChatState chatState = Config.DEFAULT_CHAT_STATE;
 
         public User(MucOptions options, Jid fullJid) {
@@ -855,7 +856,7 @@ public class MucOptions {
 
         @Override
         public String toString() {
-            return "[fulljid:" + String.valueOf(fullJid) + ",realjid:" + String.valueOf(realJid) + ",affiliation" + affiliation.toString() + "]";
+            return "[fulljid:" + fullJid + ",realjid:" + realJid + ",affiliation" + affiliation.toString() + "]";
         }
 
         public boolean realJidMatchesAccount() {

src/main/java/eu/siacs/conversations/entities/Presence.java

@@ -2,7 +2,6 @@ package eu.siacs.conversations.entities;
 
 import androidx.annotation.NonNull;
 
-import java.lang.Comparable;
 import java.util.Locale;
 
 import eu.siacs.conversations.xml.Element;
@@ -65,7 +64,7 @@ public class Presence implements Comparable<Presence> {
 	}
 
 	public int compareTo(@NonNull Presence other) {
-		return this.status.compareTo(((Presence)other).status);
+		return this.status.compareTo(other.status);
 	}
 
 	public Status getStatus() {

src/main/java/eu/siacs/conversations/entities/ServiceDiscoveryResult.java

@@ -2,26 +2,23 @@ package eu.siacs.conversations.entities;
 
 import android.content.ContentValues;
 import android.database.Cursor;
-import androidx.annotation.NonNull;
 import android.util.Base64;
-import android.util.Log;
+
+import androidx.annotation.NonNull;
 
 import com.google.common.base.Strings;
 
-import java.io.UnsupportedEncodingException;
-import java.lang.Comparable;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.List;
-
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import eu.siacs.conversations.Config;
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
 import eu.siacs.conversations.xml.Element;
 import eu.siacs.conversations.xml.Namespace;
 import eu.siacs.conversations.xmpp.forms.Data;
@@ -242,12 +239,8 @@ public class ServiceDiscoveryResult {
 			return null;
 		}
 
-		try {
+        return md.digest(s.toString().getBytes(StandardCharsets.UTF_8));
-			return md.digest(s.toString().getBytes("UTF-8"));
+    }
-		} catch (UnsupportedEncodingException e) {
-			return null;
-		}
-	}
 
 	private JSONObject toJSON() {
 		try {

src/main/java/eu/siacs/conversations/entities/TransferablePlaceholder.java

@@ -2,7 +2,7 @@ package eu.siacs.conversations.entities;
 
 public class TransferablePlaceholder implements Transferable {
 
-	private int status;
+	private final int status;
 
 	public TransferablePlaceholder(int status) {
 		this.status = status;

src/main/java/eu/siacs/conversations/generator/IqGenerator.java

@@ -29,12 +29,12 @@ import eu.siacs.conversations.entities.Conversation;
 import eu.siacs.conversations.entities.DownloadableFile;
 import eu.siacs.conversations.services.MessageArchiveService;
 import eu.siacs.conversations.services.XmppConnectionService;
-import eu.siacs.conversations.xml.Namespace;
 import eu.siacs.conversations.xml.Element;
+import eu.siacs.conversations.xml.Namespace;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.forms.Data;
 import eu.siacs.conversations.xmpp.pep.Avatar;
 import eu.siacs.conversations.xmpp.stanzas.IqPacket;
-import eu.siacs.conversations.xmpp.Jid;
 
 public class IqGenerator extends AbstractGenerator {
 
@@ -430,7 +430,7 @@ public class IqGenerator extends AbstractGenerator {
                 ByteBuffer bb = ByteBuffer.wrap(new byte[16]);
                 bb.putLong(uuid.getMostSignificantBits());
                 bb.putLong(uuid.getLeastSignificantBits());
-                return Base64.encodeToString(bb.array(), Base64.URL_SAFE | Base64.NO_PADDING | Base64.NO_WRAP) + name.substring(pos, name.length());
+                return Base64.encodeToString(bb.array(), Base64.URL_SAFE | Base64.NO_PADDING | Base64.NO_WRAP) + name.substring(pos);
             } catch (Exception e) {
                 return name;
             }

src/main/java/eu/siacs/conversations/http/HttpDownloadConnection.java

@@ -1,9 +1,10 @@
 package eu.siacs.conversations.http;
 
 import android.os.PowerManager;
-import androidx.annotation.Nullable;
 import android.util.Log;
 
+import androidx.annotation.Nullable;
+
 import com.google.common.base.Strings;
 import com.google.common.io.ByteStreams;
 
@@ -328,7 +329,7 @@ public class HttpDownloadConnection implements Transferable {
 
         private long retrieveFileSize() throws IOException {
             try {
-                Log.d(Config.LOGTAG, "retrieve file size. interactive:" + String.valueOf(interactive));
+                Log.d(Config.LOGTAG, "retrieve file size. interactive:" + interactive);
                 changeStatus(STATUS_CHECKING);
                 HttpURLConnection connection;
                 final String hostname = mUrl.getHost();

src/main/java/eu/siacs/conversations/http/SlotRequester.java

@@ -42,12 +42,12 @@ import eu.siacs.conversations.parser.IqParser;
 import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.xml.Element;
 import eu.siacs.conversations.xml.Namespace;
-import eu.siacs.conversations.xmpp.stanzas.IqPacket;
 import eu.siacs.conversations.xmpp.Jid;
+import eu.siacs.conversations.xmpp.stanzas.IqPacket;
 
 public class SlotRequester {
 
-	private XmppConnectionService service;
+	private final XmppConnectionService service;
 
 	public SlotRequester(XmppConnectionService service) {
 		this.service = service;

src/main/java/eu/siacs/conversations/parser/AbstractParser.java

@@ -3,7 +3,6 @@ package eu.siacs.conversations.parser;
 
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
-
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;
@@ -15,8 +14,8 @@ import eu.siacs.conversations.entities.MucOptions;
 import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.xml.Element;
 import eu.siacs.conversations.xmpp.InvalidJid;
-import eu.siacs.conversations.xmpp.stanzas.AbstractStanza;
 import eu.siacs.conversations.xmpp.Jid;
+import eu.siacs.conversations.xmpp.stanzas.AbstractStanza;
 
 public abstract class AbstractParser {
 
@@ -82,7 +81,7 @@ public abstract class AbstractParser {
 		} else {
 			ms = 0;
 		}
-		timestamp = timestamp.substring(0,19)+timestamp.substring(timestamp.length() -5,timestamp.length());
+		timestamp = timestamp.substring(0,19)+timestamp.substring(timestamp.length() -5);
 		dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ",Locale.US);
 		return Math.min(dateFormat.parse(timestamp).getTime()+ms, System.currentTimeMillis());
 	}

src/main/java/eu/siacs/conversations/parser/IqParser.java

@@ -1,10 +1,11 @@
 package eu.siacs.conversations.parser;
 
-import androidx.annotation.NonNull;
 import android.text.TextUtils;
 import android.util.Log;
 import android.util.Pair;
 
+import androidx.annotation.NonNull;
+
 import com.google.common.base.CharMatcher;
 import com.google.common.io.BaseEncoding;
 
@@ -35,11 +36,11 @@ import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.xml.Element;
 import eu.siacs.conversations.xml.Namespace;
 import eu.siacs.conversations.xmpp.InvalidJid;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.OnIqPacketReceived;
 import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 import eu.siacs.conversations.xmpp.forms.Data;
 import eu.siacs.conversations.xmpp.stanzas.IqPacket;
-import eu.siacs.conversations.xmpp.Jid;
 
 public class IqParser extends AbstractParser implements OnIqPacketReceived {
 

src/main/java/eu/siacs/conversations/parser/MessageParser.java

@@ -38,17 +38,17 @@ import eu.siacs.conversations.services.MessageArchiveService;
 import eu.siacs.conversations.services.QuickConversationsService;
 import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.utils.CryptoHelper;
+import eu.siacs.conversations.xml.Element;
 import eu.siacs.conversations.xml.LocalizedContent;
 import eu.siacs.conversations.xml.Namespace;
-import eu.siacs.conversations.xml.Element;
 import eu.siacs.conversations.xmpp.InvalidJid;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.OnMessagePacketReceived;
 import eu.siacs.conversations.xmpp.chatstate.ChatState;
 import eu.siacs.conversations.xmpp.jingle.JingleConnectionManager;
 import eu.siacs.conversations.xmpp.jingle.JingleRtpConnection;
 import eu.siacs.conversations.xmpp.pep.Avatar;
 import eu.siacs.conversations.xmpp.stanzas.MessagePacket;
-import eu.siacs.conversations.xmpp.Jid;
 
 public class MessageParser extends AbstractParser implements OnMessagePacketReceived {
 

src/main/java/eu/siacs/conversations/parser/PresenceParser.java

@@ -5,7 +5,6 @@ import android.util.Log;
 import java.util.ArrayList;
 import java.util.List;
 
-
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.crypto.PgpEngine;
 import eu.siacs.conversations.crypto.axolotl.AxolotlService;
@@ -22,10 +21,10 @@ import eu.siacs.conversations.utils.XmppUri;
 import eu.siacs.conversations.xml.Element;
 import eu.siacs.conversations.xml.Namespace;
 import eu.siacs.conversations.xmpp.InvalidJid;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.OnPresencePacketReceived;
 import eu.siacs.conversations.xmpp.pep.Avatar;
 import eu.siacs.conversations.xmpp.stanzas.PresencePacket;
-import eu.siacs.conversations.xmpp.Jid;
 
 public class PresenceParser extends AbstractParser implements
 		OnPresencePacketReceived {

src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java

@@ -11,11 +11,12 @@ import android.os.SystemClock;
 import android.util.Base64;
 import android.util.Log;
 
+import org.json.JSONException;
 import org.json.JSONObject;
-import org.whispersystems.libsignal.SignalProtocolAddress;
 import org.whispersystems.libsignal.IdentityKey;
 import org.whispersystems.libsignal.IdentityKeyPair;
 import org.whispersystems.libsignal.InvalidKeyException;
+import org.whispersystems.libsignal.SignalProtocolAddress;
 import org.whispersystems.libsignal.state.PreKeyRecord;
 import org.whispersystems.libsignal.state.SessionRecord;
 import org.whispersystems.libsignal.state.SignedPreKeyRecord;
@@ -36,8 +37,6 @@ import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.CopyOnWriteArrayList;
 
-import org.json.JSONException;
-
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.crypto.axolotl.AxolotlService;
 import eu.siacs.conversations.crypto.axolotl.FingerprintStatus;
@@ -57,8 +56,8 @@ import eu.siacs.conversations.utils.FtsUtils;
 import eu.siacs.conversations.utils.MimeUtils;
 import eu.siacs.conversations.utils.Resolver;
 import eu.siacs.conversations.xmpp.InvalidJid;
-import eu.siacs.conversations.xmpp.mam.MamReference;
 import eu.siacs.conversations.xmpp.Jid;
+import eu.siacs.conversations.xmpp.mam.MamReference;
 
 public class DatabaseBackend extends SQLiteOpenHelper {
 
@@ -107,7 +106,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
             + ") ON CONFLICT REPLACE"
             + ");";
 
-    private static String CREATE_SIGNED_PREKEYS_STATEMENT = "CREATE TABLE "
+    private static final String CREATE_SIGNED_PREKEYS_STATEMENT = "CREATE TABLE "
             + SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME + "("
             + SQLiteAxolotlStore.ACCOUNT + " TEXT,  "
             + SQLiteAxolotlStore.ID + " INTEGER, "
@@ -119,7 +118,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
             + ") ON CONFLICT REPLACE" +
             ");";
 
-    private static String CREATE_SESSIONS_STATEMENT = "CREATE TABLE "
+    private static final String CREATE_SESSIONS_STATEMENT = "CREATE TABLE "
             + SQLiteAxolotlStore.SESSION_TABLENAME + "("
             + SQLiteAxolotlStore.ACCOUNT + " TEXT,  "
             + SQLiteAxolotlStore.NAME + " TEXT, "
@@ -133,7 +132,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
             + ") ON CONFLICT REPLACE"
             + ");";
 
-    private static String CREATE_IDENTITIES_STATEMENT = "CREATE TABLE "
+    private static final String CREATE_IDENTITIES_STATEMENT = "CREATE TABLE "
             + SQLiteAxolotlStore.IDENTITIES_TABLENAME + "("
             + SQLiteAxolotlStore.ACCOUNT + " TEXT,  "
             + SQLiteAxolotlStore.NAME + " TEXT, "
@@ -152,9 +151,9 @@ public class DatabaseBackend extends SQLiteOpenHelper {
             + ") ON CONFLICT IGNORE"
             + ");";
 
-    private static String RESOLVER_RESULTS_TABLENAME = "resolver_results";
+    private static final String RESOLVER_RESULTS_TABLENAME = "resolver_results";
 
-    private static String CREATE_RESOLVER_RESULTS_TABLE = "create table " + RESOLVER_RESULTS_TABLENAME + "("
+    private static final String CREATE_RESOLVER_RESULTS_TABLE = "create table " + RESOLVER_RESULTS_TABLENAME + "("
             + Resolver.Result.DOMAIN + " TEXT,"
             + Resolver.Result.HOSTNAME + " TEXT,"
             + Resolver.Result.IP + " BLOB,"
@@ -165,16 +164,16 @@ public class DatabaseBackend extends SQLiteOpenHelper {
             + "UNIQUE(" + Resolver.Result.DOMAIN + ") ON CONFLICT REPLACE"
             + ");";
 
-    private static String CREATE_MESSAGE_TIME_INDEX = "create INDEX message_time_index ON " + Message.TABLENAME + "(" + Message.TIME_SENT + ")";
+    private static final String CREATE_MESSAGE_TIME_INDEX = "create INDEX message_time_index ON " + Message.TABLENAME + "(" + Message.TIME_SENT + ")";
-    private static String CREATE_MESSAGE_CONVERSATION_INDEX = "create INDEX message_conversation_index ON " + Message.TABLENAME + "(" + Message.CONVERSATION + ")";
+    private static final String CREATE_MESSAGE_CONVERSATION_INDEX = "create INDEX message_conversation_index ON " + Message.TABLENAME + "(" + Message.CONVERSATION + ")";
-    private static String CREATE_MESSAGE_DELETED_INDEX = "create index message_deleted_index ON " + Message.TABLENAME + "(" + Message.DELETED + ")";
+    private static final String CREATE_MESSAGE_DELETED_INDEX = "create index message_deleted_index ON " + Message.TABLENAME + "(" + Message.DELETED + ")";
-    private static String CREATE_MESSAGE_RELATIVE_FILE_PATH_INDEX = "create INDEX message_file_path_index ON " + Message.TABLENAME + "(" + Message.RELATIVE_FILE_PATH + ")";
+    private static final String CREATE_MESSAGE_RELATIVE_FILE_PATH_INDEX = "create INDEX message_file_path_index ON " + Message.TABLENAME + "(" + Message.RELATIVE_FILE_PATH + ")";
-    private static String CREATE_MESSAGE_TYPE_INDEX = "create INDEX message_type_index ON " + Message.TABLENAME + "(" + Message.TYPE + ")";
+    private static final String CREATE_MESSAGE_TYPE_INDEX = "create INDEX message_type_index ON " + Message.TABLENAME + "(" + Message.TYPE + ")";
 
-    private static String CREATE_MESSAGE_INDEX_TABLE = "CREATE VIRTUAL TABLE messages_index USING FTS4(uuid TEXT PRIMARY KEY, body TEXT)";
+    private static final String CREATE_MESSAGE_INDEX_TABLE = "CREATE VIRTUAL TABLE messages_index USING FTS4(uuid TEXT PRIMARY KEY, body TEXT)";
-    private static String CREATE_MESSAGE_INSERT_TRIGGER = "CREATE TRIGGER after_message_insert AFTER INSERT ON " + Message.TABLENAME + " BEGIN INSERT INTO messages_index (uuid,body) VALUES (new.uuid,new.body); END;";
+    private static final String CREATE_MESSAGE_INSERT_TRIGGER = "CREATE TRIGGER after_message_insert AFTER INSERT ON " + Message.TABLENAME + " BEGIN INSERT INTO messages_index (uuid,body) VALUES (new.uuid,new.body); END;";
-    private static String CREATE_MESSAGE_UPDATE_TRIGGER = "CREATE TRIGGER after_message_update UPDATE of uuid,body ON " + Message.TABLENAME + " BEGIN update messages_index set body=new.body,uuid=new.uuid WHERE uuid=old.uuid; END;";
+    private static final String CREATE_MESSAGE_UPDATE_TRIGGER = "CREATE TRIGGER after_message_update UPDATE of uuid,body ON " + Message.TABLENAME + " BEGIN update messages_index set body=new.body,uuid=new.uuid WHERE uuid=old.uuid; END;";
-    private static String COPY_PREEXISTING_ENTRIES = "INSERT into messages_index(uuid,body) select uuid,body FROM " + Message.TABLENAME + ";";
+    private static final String COPY_PREEXISTING_ENTRIES = "INSERT into messages_index(uuid,body) select uuid,body FROM " + Message.TABLENAME + ";";
 
     private DatabaseBackend(Context context) {
         super(context, DATABASE_NAME, null, DATABASE_VERSION);
@@ -633,7 +632,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
                 continue;
             }
 
-            String updateArgs[] = {
+            String[] updateArgs = {
                     newServer,
                     cursor.getString(cursor.getColumnIndex(Account.UUID)),
             };
@@ -872,7 +871,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
         SQLiteDatabase db = this.getReadableDatabase();
         final String SQL = "select uuid,relativeFilePath from messages where type in (1,2,5) and deleted=0 and "+Message.RELATIVE_FILE_PATH+" is not null and conversationUuid=(select uuid from conversations where accountUuid=? and (contactJid=? or contactJid like ?)) order by timeSent desc";
         final String[] args = {account, jid.toString(), jid.toString() + "/%"};
-        Cursor cursor = db.rawQuery(SQL + (limit > 0 ? " limit " + String.valueOf(limit) : ""), args);
+        Cursor cursor = db.rawQuery(SQL + (limit > 0 ? " limit " + limit : ""), args);
         List<FilePath> filesPaths = new ArrayList<>();
         while (cursor.moveToNext()) {
             filesPaths.add(new FilePath(cursor.getString(0), cursor.getString(1)));
@@ -1005,7 +1004,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
     public void readRoster(Roster roster) {
         SQLiteDatabase db = this.getReadableDatabase();
         Cursor cursor;
-        String args[] = {roster.getAccount().getUuid()};
+        String[] args = {roster.getAccount().getUuid()};
         cursor = db.query(Contact.TABLENAME, null, Contact.ACCOUNT + "=?", args, null, null, null);
         while (cursor.moveToNext()) {
             roster.initContact(Contact.fromCursor(cursor));

src/main/java/eu/siacs/conversations/persistance/FileBackend.java

@@ -20,8 +20,6 @@ import android.os.Environment;
 import android.os.ParcelFileDescriptor;
 import android.provider.MediaStore;
 import android.provider.OpenableColumns;
-import androidx.annotation.RequiresApi;
-import androidx.core.content.FileProvider;
 import android.system.Os;
 import android.system.StructStat;
 import android.util.Base64;
@@ -30,6 +28,9 @@ import android.util.DisplayMetrics;
 import android.util.Log;
 import android.util.LruCache;
 
+import androidx.annotation.RequiresApi;
+import androidx.core.content.FileProvider;
+
 import java.io.ByteArrayOutputStream;
 import java.io.Closeable;
 import java.io.File;
@@ -277,7 +278,6 @@ public class FileBackend {
         } finally {
             if (bitmap != null) {
                 bitmap.recycle();
-                ;
             }
         }
     }
@@ -982,9 +982,9 @@ public class FileBackend {
     public Uri getTakePhotoUri() {
         File file;
         if (Config.ONLY_INTERNAL_STORAGE) {
-            file = new File(mXmppConnectionService.getCacheDir().getAbsolutePath(), "Camera/IMG_" + this.IMAGE_DATE_FORMAT.format(new Date()) + ".jpg");
+            file = new File(mXmppConnectionService.getCacheDir().getAbsolutePath(), "Camera/IMG_" + IMAGE_DATE_FORMAT.format(new Date()) + ".jpg");
         } else {
-            file = new File(getTakePhotoPath() + "IMG_" + this.IMAGE_DATE_FORMAT.format(new Date()) + ".jpg");
+            file = new File(getTakePhotoPath() + "IMG_" + IMAGE_DATE_FORMAT.format(new Date()) + ".jpg");
         }
         file.getParentFile().mkdirs();
         return getUriForFile(mXmppConnectionService, file);
@@ -1408,9 +1408,6 @@ public class FileBackend {
             return null;
         }
         Bitmap bm = cropCenter(getAvatarUri(avatar), size, size);
-        if (bm == null) {
-            return null;
-        }
         return bm;
     }
 
@@ -1447,7 +1444,7 @@ public class FileBackend {
     }
 
     public static class FileCopyException extends Exception {
-        private int resId;
+        private final int resId;
 
         private FileCopyException(int resId) {
             this.resId = resId;

src/main/java/eu/siacs/conversations/persistance/OnPhoneContactsMerged.java

@@ -1,5 +1,5 @@
 package eu.siacs.conversations.persistance;
 
 public interface OnPhoneContactsMerged {
-	public void phoneContactsMerged();
+	void phoneContactsMerged();
 }

src/main/java/eu/siacs/conversations/services/AppRTCAudioManager.java

@@ -20,9 +20,10 @@ import android.media.AudioManager;
 import android.media.AudioRecord;
 import android.media.MediaRecorder;
 import android.os.Build;
-import androidx.annotation.Nullable;
 import android.util.Log;
 
+import androidx.annotation.Nullable;
+
 import org.webrtc.ThreadUtils;
 
 import java.util.Collections;
@@ -47,7 +48,7 @@ public class AppRTCAudioManager {
     // Handles all tasks related to Bluetooth headset devices.
     private final AppRTCBluetoothManager bluetoothManager;
     @Nullable
-    private AudioManager audioManager;
+    private final AudioManager audioManager;
     @Nullable
     private AudioManagerEvents audioManagerEvents;
     private AudioManagerState amState;
@@ -78,7 +79,7 @@ public class AppRTCAudioManager {
     // avoid duplicate elements.
     private Set<AudioDevice> audioDevices = new HashSet<>();
     // Broadcast receiver for wired headset intent broadcasts.
-    private BroadcastReceiver wiredHeadsetReceiver;
+    private final BroadcastReceiver wiredHeadsetReceiver;
     // Callback method for changes in audio focus.
     @Nullable
     private AudioManager.OnAudioFocusChangeListener audioFocusChangeListener;

src/main/java/eu/siacs/conversations/services/AppRTCBluetoothManager.java

@@ -23,14 +23,15 @@ import android.media.AudioManager;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.Process;
-import androidx.annotation.Nullable;
 import android.util.Log;
 
+import androidx.annotation.Nullable;
+
+import org.webrtc.ThreadUtils;
+
 import java.util.List;
 import java.util.Set;
 
-import org.webrtc.ThreadUtils;
-
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.utils.AppRTCUtils;
 

src/main/java/eu/siacs/conversations/services/AppRTCProximitySensor.java

@@ -15,9 +15,10 @@ import android.hardware.SensorEvent;
 import android.hardware.SensorEventListener;
 import android.hardware.SensorManager;
 import android.os.Build;
-import androidx.annotation.Nullable;
 import android.util.Log;
 
+import androidx.annotation.Nullable;
+
 import org.webrtc.ThreadUtils;
 
 import eu.siacs.conversations.Config;

src/main/java/eu/siacs/conversations/services/AttachFileToConversationRunnable.java

@@ -6,19 +6,18 @@ import android.net.Uri;
 import android.os.Build;
 import android.os.ParcelFileDescriptor;
 import android.preference.PreferenceManager;
-import androidx.annotation.RequiresApi;
 import android.util.Log;
 
+import androidx.annotation.RequiresApi;
+
 import net.ypresto.androidtranscoder.MediaTranscoder;
 import net.ypresto.androidtranscoder.format.MediaFormatStrategy;
-import net.ypresto.androidtranscoder.format.MediaFormatStrategyPresets;
 
 import java.io.File;
 import java.io.FileDescriptor;
 import java.io.FileNotFoundException;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
-import java.util.concurrent.atomic.AtomicInteger;
 
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.R;

src/main/java/eu/siacs/conversations/services/AvatarService.java

@@ -12,15 +12,15 @@ import android.graphics.Typeface;
 import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
-import androidx.annotation.ColorInt;
-import androidx.annotation.Nullable;
-import androidx.core.content.res.ResourcesCompat;
 import android.text.TextUtils;
 import android.util.DisplayMetrics;
 import android.util.Log;
 import android.util.LruCache;
 
-import java.util.ArrayList;
+import androidx.annotation.ColorInt;
+import androidx.annotation.Nullable;
+import androidx.core.content.res.ResourcesCompat;
+
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -40,9 +40,9 @@ import eu.siacs.conversations.entities.MucOptions;
 import eu.siacs.conversations.entities.RawBlockable;
 import eu.siacs.conversations.entities.Room;
 import eu.siacs.conversations.utils.UIHelper;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.OnAdvancedStreamFeaturesLoaded;
 import eu.siacs.conversations.xmpp.XmppConnection;
-import eu.siacs.conversations.xmpp.Jid;
 
 public class AvatarService implements OnAdvancedStreamFeaturesLoaded {
 
@@ -519,7 +519,7 @@ public class AvatarService implements OnAdvancedStreamFeaturesLoaded {
 			this.sizes.add(size);
 		}
 		return PREFIX_ACCOUNT + "_" + account.getUuid() + "_"
-				+ String.valueOf(size);
+				+ size;
 	}
 
 	/*public Bitmap get(String name, int size) {

src/main/java/eu/siacs/conversations/services/BarcodeProvider.java

@@ -13,9 +13,10 @@ import android.net.Uri;
 import android.os.CancellationSignal;
 import android.os.IBinder;
 import android.os.ParcelFileDescriptor;
-import androidx.annotation.Nullable;
 import android.util.Log;
 
+import androidx.annotation.Nullable;
+
 import com.google.zxing.BarcodeFormat;
 import com.google.zxing.EncodeHintType;
 import com.google.zxing.common.BitMatrix;

src/main/java/eu/siacs/conversations/services/ChannelDiscoveryService.java

@@ -1,8 +1,9 @@
 package eu.siacs.conversations.services;
 
-import androidx.annotation.NonNull;
 import android.util.Log;
 
+import androidx.annotation.NonNull;
+
 import com.google.common.cache.Cache;
 import com.google.common.cache.CacheBuilder;
 
@@ -22,6 +23,7 @@ import eu.siacs.conversations.entities.Room;
 import eu.siacs.conversations.http.HttpConnectionManager;
 import eu.siacs.conversations.http.services.MuclumbusService;
 import eu.siacs.conversations.parser.IqParser;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.OnIqPacketReceived;
 import eu.siacs.conversations.xmpp.XmppConnection;
 import eu.siacs.conversations.xmpp.stanzas.IqPacket;
@@ -32,7 +34,6 @@ import retrofit2.Callback;
 import retrofit2.Response;
 import retrofit2.Retrofit;
 import retrofit2.converter.gson.GsonConverterFactory;
-import eu.siacs.conversations.xmpp.Jid;
 
 public class ChannelDiscoveryService {
 

src/main/java/eu/siacs/conversations/services/EventReceiver.java

@@ -5,9 +5,6 @@ import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
 import android.preference.PreferenceManager;
-
-import androidx.core.content.ContextCompat;
-
 import android.util.Log;
 
 import com.google.common.base.Strings;

src/main/java/eu/siacs/conversations/services/ExportBackupService.java

@@ -11,9 +11,10 @@ import android.database.DatabaseUtils;
 import android.database.sqlite.SQLiteDatabase;
 import android.net.Uri;
 import android.os.IBinder;
-import androidx.core.app.NotificationCompat;
 import android.util.Log;
 
+import androidx.core.app.NotificationCompat;
+
 import com.google.common.base.Strings;
 
 import java.io.DataOutputStream;

src/main/java/eu/siacs/conversations/services/MemorizingTrustManager.java

@@ -34,11 +34,12 @@ import android.content.Intent;
 import android.net.Uri;
 import android.os.Handler;
 import android.preference.PreferenceManager;
-import androidx.appcompat.app.AppCompatActivity;
 import android.util.Base64;
 import android.util.Log;
 import android.util.SparseArray;
 
+import androidx.appcompat.app.AppCompatActivity;
+
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
@@ -114,14 +115,14 @@ public class MemorizingTrustManager {
     static String KEYSTORE_DIR = "KeyStore";
     static String KEYSTORE_FILE = "KeyStore.bks";
     private static int decisionId = 0;
-    private static SparseArray<MTMDecision> openDecisions = new SparseArray<MTMDecision>();
+    private static final SparseArray<MTMDecision> openDecisions = new SparseArray<MTMDecision>();
     Context master;
     AppCompatActivity foregroundAct;
     NotificationManager notificationManager;
     Handler masterHandler;
     private File keyStoreFile;
     private KeyStore appKeyStore;
-    private X509TrustManager defaultTrustManager;
+    private final X509TrustManager defaultTrustManager;
     private X509TrustManager appTrustManager;
     private String poshCacheDir;
 
@@ -699,7 +700,7 @@ public class MemorizingTrustManager {
                 Object name = altName.get(1);
                 if (name instanceof String) {
                     si.append("[");
-                    si.append((Integer) altName.get(0));
+                    si.append(altName.get(0));
                     si.append("] ");
                     si.append(name);
                     si.append("\n");

src/main/java/eu/siacs/conversations/services/MessageArchiveService.java

@@ -18,11 +18,11 @@ import eu.siacs.conversations.entities.Conversational;
 import eu.siacs.conversations.entities.ReceiptRequest;
 import eu.siacs.conversations.generator.AbstractGenerator;
 import eu.siacs.conversations.xml.Element;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.OnAdvancedStreamFeaturesLoaded;
 import eu.siacs.conversations.xmpp.mam.MamReference;
 import eu.siacs.conversations.xmpp.stanzas.IqPacket;
 import eu.siacs.conversations.xmpp.stanzas.MessagePacket;
-import eu.siacs.conversations.xmpp.Jid;
 
 public class MessageArchiveService implements OnAdvancedStreamFeaturesLoaded {
 
@@ -89,9 +89,9 @@ public class MessageArchiveService implements OnAdvancedStreamFeaturesLoaded {
 			return null;
 		}
 
-	};
+	}
 
-	MessageArchiveService(final XmppConnectionService service) {
+    MessageArchiveService(final XmppConnectionService service) {
 		this.mXmppConnectionService = service;
 	}
 
@@ -370,7 +370,7 @@ public class MessageArchiveService implements OnAdvancedStreamFeaturesLoaded {
 			done = done || (query.getActualMessageCount() == 0 && !query.isCatchup());
 			this.finalizeQuery(query, done);
 
-			Log.d(Config.LOGTAG, query.getAccount().getJid().asBareJid() + ": finished mam after " + query.getTotalCount() + "(" + query.getActualMessageCount() + ") messages. messages left=" + Boolean.toString(!done) + " count=" + count);
+			Log.d(Config.LOGTAG, query.getAccount().getJid().asBareJid() + ": finished mam after " + query.getTotalCount() + "(" + query.getActualMessageCount() + ") messages. messages left=" + !done + " count=" + count);
 			if (query.isCatchup() && query.getActualMessageCount() > 0) {
 				mXmppConnectionService.getNotificationService().finishBacklog(true, query.getAccount());
 			}
@@ -459,10 +459,10 @@ public class MessageArchiveService implements OnAdvancedStreamFeaturesLoaded {
 		private int actualCount = 0;
 		private int actualInThisQuery = 0;
 		private long start;
-		private long end;
+		private final long end;
-		private String queryId;
+		private final String queryId;
 		private String reference = null;
-		private Account account;
+		private final Account account;
 		private Conversation conversation;
 		private PagingOrder pagingOrder = PagingOrder.NORMAL;
 		private XmppConnectionService.OnMoreMessagesLoaded callback = null;
@@ -649,7 +649,7 @@ public class MessageArchiveService implements OnAdvancedStreamFeaturesLoaded {
 				}
 				builder.append(this.reference);
 			}
-			builder.append(", catchup=").append(Boolean.toString(catchup));
+			builder.append(", catchup=").append(catchup);
 			builder.append(", ns=").append(version.namespace);
 			return builder.toString();
 		}

src/main/java/eu/siacs/conversations/services/NotificationService.java

@@ -17,6 +17,11 @@ import android.net.Uri;
 import android.os.Build;
 import android.os.SystemClock;
 import android.preference.PreferenceManager;
+import android.text.SpannableString;
+import android.text.style.StyleSpan;
+import android.util.DisplayMetrics;
+import android.util.Log;
+
 import androidx.annotation.RequiresApi;
 import androidx.core.app.NotificationCompat;
 import androidx.core.app.NotificationCompat.BigPictureStyle;
@@ -26,10 +31,6 @@ import androidx.core.app.Person;
 import androidx.core.app.RemoteInput;
 import androidx.core.content.ContextCompat;
 import androidx.core.graphics.drawable.IconCompat;
-import android.text.SpannableString;
-import android.text.style.StyleSpan;
-import android.util.DisplayMetrics;
-import android.util.Log;
 
 import java.io.File;
 import java.io.IOException;

src/main/java/eu/siacs/conversations/services/ShortcutService.java

@@ -8,9 +8,10 @@ import android.graphics.Bitmap;
 import android.graphics.drawable.Icon;
 import android.net.Uri;
 import android.os.Build;
-import androidx.annotation.NonNull;
 import android.util.Log;
 
+import androidx.annotation.NonNull;
+
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;

src/main/java/eu/siacs/conversations/services/XmppConnectionService.java

@@ -460,8 +460,8 @@ public class XmppConnectionService extends Service {
     private WakeLock wakeLock;
     private PowerManager pm;
     private LruCache<String, Bitmap> mBitmapCache;
-    private BroadcastReceiver mInternalEventReceiver = new InternalEventReceiver();
+    private final BroadcastReceiver mInternalEventReceiver = new InternalEventReceiver();
-    private BroadcastReceiver mInternalScreenEventReceiver = new InternalEventReceiver();
+    private final BroadcastReceiver mInternalScreenEventReceiver = new InternalEventReceiver();
 
     private static String generateFetchKey(Account account, final Avatar avatar) {
         return account.getJid().asBareJid() + "_" + avatar.owner + "_" + avatar.sha1sum;
@@ -800,7 +800,7 @@ public class XmppConnectionService extends Service {
                 for (Account account : pingCandidates) {
                     final boolean lowTimeout = isInLowPingTimeoutMode(account);
                     account.getXmppConnection().sendPing();
-                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + " send ping (action=" + action + ",lowTimeout=" + Boolean.toString(lowTimeout) + ")");
+                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + " send ping (action=" + action + ",lowTimeout=" + lowTimeout + ")");
                     scheduleWakeUpCall(lowTimeout ? Config.LOW_PING_TIMEOUT : Config.PING_TIMEOUT, account.getUuid().hashCode());
                 }
             }
@@ -1840,7 +1840,7 @@ public class XmppConnectionService extends Service {
                     }
                 });
             } else {
-                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": error publishing bookmarks (retry=" + Boolean.toString(retry) + ") " + response);
+                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": error publishing bookmarks (retry=" + retry + ") " + response);
             }
         });
     }

src/main/java/eu/siacs/conversations/ui/AboutActivity.java

@@ -1,7 +1,7 @@
 package eu.siacs.conversations.ui;
 
 import android.os.Bundle;
-import android.preference.PreferenceManager;
+
 import androidx.appcompat.app.AppCompatActivity;
 
 import eu.siacs.conversations.R;

src/main/java/eu/siacs/conversations/ui/AbstractSearchableListItemActivity.java

@@ -1,9 +1,7 @@
 package eu.siacs.conversations.ui;
 
 import android.content.Context;
-import androidx.databinding.DataBindingUtil;
 import android.os.Bundle;
-import androidx.appcompat.widget.Toolbar;
 import android.text.Editable;
 import android.text.TextWatcher;
 import android.view.KeyEvent;
@@ -16,6 +14,8 @@ import android.widget.EditText;
 import android.widget.ListView;
 import android.widget.TextView;
 
+import androidx.databinding.DataBindingUtil;
+
 import java.util.ArrayList;
 import java.util.List;
 
@@ -92,7 +92,7 @@ public abstract class AbstractSearchableListItemActivity extends XmppActivity im
 	public void onCreate(final Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 		this.binding = DataBindingUtil.setContentView(this,R.layout.activity_choose_contact);
-		setSupportActionBar((Toolbar) binding.toolbar);
+		setSupportActionBar(binding.toolbar);
 		configureActionBar(getSupportActionBar());
 		this.binding.chooseContactList.setFastScrollEnabled(true);
 		mListItemsAdapter = new ListItemAdapter(this, listItems);

src/main/java/eu/siacs/conversations/ui/ActionBarActivity.java

@@ -1,8 +1,11 @@
 package eu.siacs.conversations.ui;
 
+import android.view.MenuItem;
+import android.view.View;
+
 import androidx.appcompat.app.ActionBar;
 import androidx.appcompat.app.AppCompatActivity;
-import android.view.MenuItem;
+import androidx.appcompat.widget.Toolbar;
 
 
 public abstract class ActionBarActivity extends AppCompatActivity {
@@ -17,6 +20,10 @@ public abstract class ActionBarActivity extends AppCompatActivity {
         }
     }
 
+    public void setSupportActionBar(View toolbar) {
+        super.setSupportActionBar((Toolbar) toolbar);
+    }
+
     @Override
     public boolean onOptionsItemSelected(final MenuItem item) {
         switch (item.getItemId()) {

src/main/java/eu/siacs/conversations/ui/BlockContactDialog.java

@@ -1,11 +1,12 @@
 package eu.siacs.conversations.ui;
 
-import androidx.databinding.DataBindingUtil;
-import androidx.annotation.StringRes;
-import androidx.appcompat.app.AlertDialog;
 import android.view.View;
 import android.widget.Toast;
 
+import androidx.annotation.StringRes;
+import androidx.appcompat.app.AlertDialog;
+import androidx.databinding.DataBindingUtil;
+
 import eu.siacs.conversations.R;
 import eu.siacs.conversations.databinding.DialogBlockContactBinding;
 import eu.siacs.conversations.entities.Blockable;

src/main/java/eu/siacs/conversations/ui/BlocklistActivity.java

@@ -1,11 +1,12 @@
 package eu.siacs.conversations.ui;
 
 import android.os.Bundle;
-import androidx.fragment.app.Fragment;
-import androidx.fragment.app.FragmentTransaction;
 import android.text.Editable;
 import android.widget.Toast;
 
+import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentTransaction;
+
 import java.util.Collections;
 
 import eu.siacs.conversations.R;
@@ -14,8 +15,8 @@ import eu.siacs.conversations.entities.Blockable;
 import eu.siacs.conversations.entities.ListItem;
 import eu.siacs.conversations.entities.RawBlockable;
 import eu.siacs.conversations.ui.interfaces.OnBackendConnected;
-import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 import eu.siacs.conversations.xmpp.Jid;
+import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 
 public class BlocklistActivity extends AbstractSearchableListItemActivity implements OnUpdateBlocklist {
 

src/main/java/eu/siacs/conversations/ui/ChangePasswordActivity.java

@@ -2,12 +2,13 @@ package eu.siacs.conversations.ui;
 
 import android.content.Intent;
 import android.os.Bundle;
-import com.google.android.material.textfield.TextInputLayout;
 import android.view.View;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.Toast;
 
+import com.google.android.material.textfield.TextInputLayout;
+
 import eu.siacs.conversations.R;
 import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.services.XmppConnectionService;
@@ -16,7 +17,7 @@ import eu.siacs.conversations.ui.widget.DisabledActionModeCallback;
 public class ChangePasswordActivity extends XmppActivity implements XmppConnectionService.OnAccountPasswordChanged {
 
 	private Button mChangePasswordButton;
-	private View.OnClickListener mOnChangePasswordButtonClicked = new View.OnClickListener() {
+	private final View.OnClickListener mOnChangePasswordButtonClicked = new View.OnClickListener() {
 		@Override
 		public void onClick(View view) {
 			if (mAccount != null) {

src/main/java/eu/siacs/conversations/ui/ChannelDiscoveryActivity.java

@@ -4,11 +4,9 @@ import android.app.AlertDialog;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
-import androidx.databinding.DataBindingUtil;
 import android.net.Uri;
 import android.os.Bundle;
 import android.preference.PreferenceManager;
-import androidx.appcompat.widget.Toolbar;
 import android.text.Html;
 import android.text.method.LinkMovementMethod;
 import android.view.KeyEvent;
@@ -20,6 +18,8 @@ import android.widget.EditText;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.databinding.DataBindingUtil;
+
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicReference;
@@ -77,7 +77,7 @@ public class ChannelDiscoveryActivity extends XmppActivity implements MenuItem.O
     protected void onCreate(final Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         binding = DataBindingUtil.setContentView(this, R.layout.activity_channel_discovery);
-        setSupportActionBar((Toolbar) binding.toolbar);
+        setSupportActionBar(binding.toolbar);
         configureActionBar(getSupportActionBar(), true);
         binding.list.setAdapter(this.adapter);
         this.adapter.setOnChannelSearchResultSelectedListener(this);

src/main/java/eu/siacs/conversations/ui/ChooseContactActivity.java

@@ -5,11 +5,6 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.os.Bundle;
-import androidx.annotation.NonNull;
-import androidx.annotation.StringRes;
-import androidx.fragment.app.Fragment;
-import androidx.fragment.app.FragmentTransaction;
-import androidx.appcompat.app.ActionBar;
 import android.view.ActionMode;
 import android.view.KeyEvent;
 import android.view.Menu;
@@ -21,6 +16,12 @@ import android.widget.AdapterView;
 import android.widget.ListView;
 import android.widget.TextView;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.StringRes;
+import androidx.appcompat.app.ActionBar;
+import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentTransaction;
+
 import com.google.common.base.Strings;
 
 import java.util.ArrayList;
@@ -50,15 +51,15 @@ public class ChooseContactActivity extends AbstractSearchableListItemActivity im
     public static final String EXTRA_SHOW_ENTER_JID = "extra_show_enter_jid";
     public static final String EXTRA_CONVERSATION = "extra_conversation";
     private static final String EXTRA_FILTERED_CONTACTS = "extra_filtered_contacts";
-    private List<String> mActivatedAccounts = new ArrayList<>();
+    private final List<String> mActivatedAccounts = new ArrayList<>();
-    private Set<String> selected = new HashSet<>();
+    private final Set<String> selected = new HashSet<>();
     private Set<String> filterContacts;
 
     private boolean showEnterJid = false;
     private boolean startSearching = false;
     private boolean multiple = false;
 
-    private PendingItem<ActivityResult> postponedActivityResult = new PendingItem<>();
+    private final PendingItem<ActivityResult> postponedActivityResult = new PendingItem<>();
 
     public static Intent create(Activity activity, Conversation conversation) {
         final Intent intent = new Intent(activity, ChooseContactActivity.class);
@@ -380,7 +381,7 @@ public class ChooseContactActivity extends AbstractSearchableListItemActivity im
     }
 
     @Override
-    public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
         ScanActivity.onRequestPermissionResult(this, requestCode, grantResults);
     }
 

src/main/java/eu/siacs/conversations/ui/ConferenceDetailsActivity.java

@@ -3,10 +3,7 @@ package eu.siacs.conversations.ui;
 import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
-import androidx.databinding.DataBindingUtil;
 import android.os.Bundle;
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.widget.Toolbar;
 import android.text.Editable;
 import android.text.SpannableStringBuilder;
 import android.text.TextWatcher;
@@ -16,6 +13,9 @@ import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Toast;
 
+import androidx.appcompat.app.AlertDialog;
+import androidx.databinding.DataBindingUtil;
+
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -48,8 +48,8 @@ import eu.siacs.conversations.utils.EmojiWrapper;
 import eu.siacs.conversations.utils.StringUtils;
 import eu.siacs.conversations.utils.StylingHelper;
 import eu.siacs.conversations.utils.XmppUri;
-import me.drakeet.support.toast.ToastCompat;
 import eu.siacs.conversations.xmpp.Jid;
+import me.drakeet.support.toast.ToastCompat;
 
 import static eu.siacs.conversations.entities.Bookmark.printableValue;
 import static eu.siacs.conversations.utils.StringUtils.changed;
@@ -65,7 +65,7 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
 
     private boolean mAdvancedMode = false;
 
-    private UiCallback<Conversation> renameCallback = new UiCallback<Conversation>() {
+    private final UiCallback<Conversation> renameCallback = new UiCallback<Conversation>() {
         @Override
         public void success(Conversation object) {
             displayToast(getString(R.string.your_nick_has_been_changed));
@@ -86,7 +86,7 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
         }
     };
 
-    private OnClickListener mNotifyStatusClickListener = new OnClickListener() {
+    private final OnClickListener mNotifyStatusClickListener = new OnClickListener() {
         @Override
         public void onClick(View v) {
             AlertDialog.Builder builder = new AlertDialog.Builder(ConferenceDetailsActivity.this);
@@ -118,7 +118,7 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
         }
     };
 
-    private OnClickListener mChangeConferenceSettings = new OnClickListener() {
+    private final OnClickListener mChangeConferenceSettings = new OnClickListener() {
         @Override
         public void onClick(View v) {
             final MucOptions mucOptions = mConversation.getMucOptions();
@@ -160,7 +160,7 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
         super.onCreate(savedInstanceState);
         this.binding = DataBindingUtil.setContentView(this, R.layout.activity_muc_details);
         this.binding.changeConferenceButton.setOnClickListener(this.mChangeConferenceSettings);
-        setSupportActionBar((Toolbar) binding.toolbar);
+        setSupportActionBar(binding.toolbar);
         configureActionBar(getSupportActionBar());
         this.binding.editNickButton.setOnClickListener(v -> quickEdit(mConversation.getMucOptions().getActualNick(),
                 R.string.nickname,

src/main/java/eu/siacs/conversations/ui/ContactDetailsActivity.java

@@ -6,7 +6,6 @@ import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
-import androidx.databinding.DataBindingUtil;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
@@ -14,9 +13,6 @@ import android.preference.PreferenceManager;
 import android.provider.ContactsContract.CommonDataKinds;
 import android.provider.ContactsContract.Contacts;
 import android.provider.ContactsContract.Intents;
-import androidx.annotation.NonNull;
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.widget.Toolbar;
 import android.text.Spannable;
 import android.text.SpannableString;
 import android.text.style.RelativeSizeSpan;
@@ -30,6 +26,10 @@ import android.widget.CompoundButton.OnCheckedChangeListener;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AlertDialog;
+import androidx.databinding.DataBindingUtil;
+
 import org.openintents.openpgp.util.OpenPgpUtils;
 
 import java.util.Collection;
@@ -73,14 +73,14 @@ public class ContactDetailsActivity extends OmemoActivity implements OnAccountUp
     private MediaAdapter mMediaAdapter;
 
     private Contact contact;
-    private DialogInterface.OnClickListener removeFromRoster = new DialogInterface.OnClickListener() {
+    private final DialogInterface.OnClickListener removeFromRoster = new DialogInterface.OnClickListener() {
 
         @Override
         public void onClick(DialogInterface dialog, int which) {
             xmppConnectionService.deleteContactOnServer(contact);
         }
     };
-    private OnCheckedChangeListener mOnSendCheckedChange = new OnCheckedChangeListener() {
+    private final OnCheckedChangeListener mOnSendCheckedChange = new OnCheckedChangeListener() {
 
         @Override
         public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
@@ -96,7 +96,7 @@ public class ContactDetailsActivity extends OmemoActivity implements OnAccountUp
             }
         }
     };
-    private OnCheckedChangeListener mOnReceiveCheckedChange = new OnCheckedChangeListener() {
+    private final OnCheckedChangeListener mOnReceiveCheckedChange = new OnCheckedChangeListener() {
 
         @Override
         public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
@@ -197,7 +197,7 @@ public class ContactDetailsActivity extends OmemoActivity implements OnAccountUp
         this.messageFingerprint = getIntent().getStringExtra("fingerprint");
         this.binding = DataBindingUtil.setContentView(this, R.layout.activity_contact_details);
 
-        setSupportActionBar((Toolbar) binding.toolbar);
+        setSupportActionBar(binding.toolbar);
         configureActionBar(getSupportActionBar());
         binding.showInactiveDevices.setOnClickListener(v -> {
             showInactiveOmemo = !showInactiveOmemo;
@@ -232,7 +232,7 @@ public class ContactDetailsActivity extends OmemoActivity implements OnAccountUp
     }
 
     @Override
-    public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
         if (grantResults.length > 0)
             if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                 if (requestCode == REQUEST_SYNC_CONTACTS && xmppConnectionServiceBound) {
@@ -371,22 +371,14 @@ public class ContactDetailsActivity extends OmemoActivity implements OnAccountUp
                 binding.detailsSendPresence.setText(R.string.send_presence_updates);
             } else {
                 binding.detailsSendPresence.setText(R.string.preemptively_grant);
-                if (contact.getOption(Contact.Options.PREEMPTIVE_GRANT)) {
+                binding.detailsSendPresence.setChecked(contact.getOption(Contact.Options.PREEMPTIVE_GRANT));
-                    binding.detailsSendPresence.setChecked(true);
-                } else {
-                    binding.detailsSendPresence.setChecked(false);
-                }
             }
             if (contact.getOption(Contact.Options.TO)) {
                 binding.detailsReceivePresence.setText(R.string.receive_presence_updates);
                 binding.detailsReceivePresence.setChecked(true);
             } else {
                 binding.detailsReceivePresence.setText(R.string.ask_for_presence_updates);
-                if (contact.getOption(Contact.Options.ASKING)) {
+                binding.detailsReceivePresence.setChecked(contact.getOption(Contact.Options.ASKING));
-                    binding.detailsReceivePresence.setChecked(true);
-                } else {
-                    binding.detailsReceivePresence.setChecked(false);
-                }
             }
             if (contact.getAccount().isOnlineAndConnected()) {
                 binding.detailsReceivePresence.setEnabled(true);
@@ -476,8 +468,8 @@ public class ContactDetailsActivity extends OmemoActivity implements OnAccountUp
         if (Config.supportOpenPgp() && contact.getPgpKeyId() != 0) {
             hasKeys = true;
             View view = inflater.inflate(R.layout.contact_key, binding.detailsContactKeys, false);
-            TextView key = (TextView) view.findViewById(R.id.key);
+            TextView key = view.findViewById(R.id.key);
-            TextView keyType = (TextView) view.findViewById(R.id.key_type);
+            TextView keyType = view.findViewById(R.id.key_type);
             keyType.setText(R.string.openpgp_key_id);
             if ("pgp".equals(messageFingerprint)) {
                 keyType.setTextAppearance(this, R.style.TextAppearance_Conversations_Caption_Highlight);

src/main/java/eu/siacs/conversations/ui/ConversationActivity.java

@@ -2,6 +2,7 @@ package eu.siacs.conversations.ui;
 
 import android.content.Intent;
 import android.os.Bundle;
+
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
 

src/main/java/eu/siacs/conversations/ui/ConversationFragment.java

@@ -3,29 +3,22 @@ package eu.siacs.conversations.ui;
 import android.Manifest;
 import android.annotation.SuppressLint;
 import android.app.Activity;
-import android.app.FragmentManager;
-import android.content.SharedPreferences;
-import android.content.pm.PackageManager;
-import androidx.databinding.DataBindingUtil;
-import android.net.Uri;
-import android.os.Build;
-import android.preference.PreferenceManager;
-import android.provider.MediaStore;
-import androidx.annotation.IdRes;
-import androidx.annotation.NonNull;
-import androidx.annotation.StringRes;
-import androidx.appcompat.app.AlertDialog;
 import android.app.Fragment;
+import android.app.FragmentManager;
 import android.app.PendingIntent;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.IntentSender.SendIntentException;
+import android.content.SharedPreferences;
+import android.content.pm.PackageManager;
+import android.net.Uri;
+import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.SystemClock;
-import androidx.core.view.inputmethod.InputConnectionCompat;
+import android.preference.PreferenceManager;
-import androidx.core.view.inputmethod.InputContentInfoCompat;
+import android.provider.MediaStore;
 import android.text.Editable;
 import android.text.TextUtils;
 import android.util.Log;
@@ -52,6 +45,14 @@ import android.widget.PopupMenu;
 import android.widget.TextView.OnEditorActionListener;
 import android.widget.Toast;
 
+import androidx.annotation.IdRes;
+import androidx.annotation.NonNull;
+import androidx.annotation.StringRes;
+import androidx.appcompat.app.AlertDialog;
+import androidx.core.view.inputmethod.InputConnectionCompat;
+import androidx.core.view.inputmethod.InputContentInfoCompat;
+import androidx.databinding.DataBindingUtil;
+
 import com.google.common.base.Optional;
 
 import java.util.ArrayList;
@@ -117,6 +118,7 @@ import eu.siacs.conversations.utils.StylingHelper;
 import eu.siacs.conversations.utils.TimeFrameUtils;
 import eu.siacs.conversations.utils.UIHelper;
 import eu.siacs.conversations.xml.Namespace;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.XmppConnection;
 import eu.siacs.conversations.xmpp.chatstate.ChatState;
 import eu.siacs.conversations.xmpp.jingle.AbstractJingleConnection;
@@ -125,7 +127,6 @@ import eu.siacs.conversations.xmpp.jingle.JingleFileTransferConnection;
 import eu.siacs.conversations.xmpp.jingle.Media;
 import eu.siacs.conversations.xmpp.jingle.OngoingRtpSession;
 import eu.siacs.conversations.xmpp.jingle.RtpCapability;
-import eu.siacs.conversations.xmpp.Jid;
 
 import static eu.siacs.conversations.ui.XmppActivity.EXTRA_ACCOUNT;
 import static eu.siacs.conversations.ui.XmppActivity.REQUEST_INVITE_TO_CONVERSATION;
@@ -848,7 +849,7 @@ public class ConversationFragment extends XmppFragment implements EditMessage.Ke
             case ATTACHMENT_CHOICE_LOCATION:
                 double latitude = data.getDoubleExtra("latitude", 0);
                 double longitude = data.getDoubleExtra("longitude", 0);
-                Uri geo = Uri.parse("geo:" + String.valueOf(latitude) + "," + String.valueOf(longitude));
+                Uri geo = Uri.parse("geo:" + latitude + "," + longitude);
                 mediaPreviewAdapter.addMediaPreviews(Attachment.of(getActivity(), geo, Attachment.Type.LOCATION));
                 toggleInputMethod();
                 break;
@@ -2099,7 +2100,7 @@ public class ConversationFragment extends XmppFragment implements EditMessage.Ke
         }
 
         stopScrolling();
-        Log.d(Config.LOGTAG, "reInit(hasExtras=" + Boolean.toString(hasExtras) + ")");
+        Log.d(Config.LOGTAG, "reInit(hasExtras=" + hasExtras + ")");
 
         if (this.conversation.isRead() && hasExtras) {
             Log.d(Config.LOGTAG, "trimming conversation");
@@ -2122,7 +2123,7 @@ public class ConversationFragment extends XmppFragment implements EditMessage.Ke
         refresh(false);
         activity.invalidateOptionsMenu();
         this.conversation.messagesLoaded.set(true);
-        Log.d(Config.LOGTAG, "scrolledToBottomAndNoPending=" + Boolean.toString(scrolledToBottomAndNoPending));
+        Log.d(Config.LOGTAG, "scrolledToBottomAndNoPending=" + scrolledToBottomAndNoPending);
 
         if (hasExtras || scrolledToBottomAndNoPending) {
             resetUnreadMessagesCount();

src/main/java/eu/siacs/conversations/ui/ConversationsActivity.java

@@ -39,21 +39,21 @@ import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.Intent;
 import android.content.pm.PackageManager;
-import androidx.databinding.DataBindingUtil;
 import android.net.Uri;
 import android.os.Bundle;
 import android.provider.Settings;
-import androidx.annotation.IdRes;
-import androidx.annotation.NonNull;
-import androidx.appcompat.app.ActionBar;
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.widget.Toolbar;
 import android.util.Log;
 import android.view.KeyEvent;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.widget.Toast;
 
+import androidx.annotation.IdRes;
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.ActionBar;
+import androidx.appcompat.app.AlertDialog;
+import androidx.databinding.DataBindingUtil;
+
 import org.openintents.openpgp.util.OpenPgpApi;
 
 import java.util.Arrays;
@@ -80,8 +80,8 @@ import eu.siacs.conversations.utils.EmojiWrapper;
 import eu.siacs.conversations.utils.ExceptionHelper;
 import eu.siacs.conversations.utils.SignupUtils;
 import eu.siacs.conversations.utils.XmppUri;
-import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 import eu.siacs.conversations.xmpp.Jid;
+import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 
 import static eu.siacs.conversations.ui.ConversationFragment.REQUEST_DECRYPT_PGP;
 
@@ -97,7 +97,7 @@ public class ConversationsActivity extends XmppActivity implements OnConversatio
     public static final String EXTRA_POST_INIT_ACTION = "post_init_action";
     public static final String POST_ACTION_RECORD_VOICE = "record_voice";
 
-    private static List<String> VIEW_AND_SHARE_ACTIONS = Arrays.asList(
+    private static final List<String> VIEW_AND_SHARE_ACTIONS = Arrays.asList(
             ACTION_VIEW_CONVERSATION,
             Intent.ACTION_SEND,
             Intent.ACTION_SEND_MULTIPLE
@@ -114,7 +114,7 @@ public class ConversationsActivity extends XmppActivity implements OnConversatio
     private final PendingItem<ActivityResult> postponedActivityResult = new PendingItem<>();
     private ActivityConversationsBinding binding;
     private boolean mActivityPaused = true;
-    private AtomicBoolean mRedirectInProcess = new AtomicBoolean(false);
+    private final AtomicBoolean mRedirectInProcess = new AtomicBoolean(false);
 
     private static boolean isViewOrShareIntent(Intent i) {
         Log.d(Config.LOGTAG, "action: " + (i == null ? null : i.getAction()));
@@ -359,7 +359,7 @@ public class ConversationsActivity extends XmppActivity implements OnConversatio
         ConversationMenuConfigurator.reloadFeatures(this);
         OmemoSetting.load(this);
         this.binding = DataBindingUtil.setContentView(this, R.layout.activity_conversations);
-        setSupportActionBar((Toolbar) binding.toolbar);
+        setSupportActionBar(binding.toolbar);
         configureActionBar(getSupportActionBar());
         this.getFragmentManager().addOnBackStackChangedListener(this::invalidateActionBarTitle);
         this.getFragmentManager().addOnBackStackChangedListener(this::showDialogsIfMainIsOverview);
@@ -660,7 +660,7 @@ public class ConversationsActivity extends XmppActivity implements OnConversatio
         if (!mActivityPaused && pendingViewIntent.peek() == null) {
             xmppConnectionService.sendReadMarker(conversation, upToUuid);
         } else {
-            Log.d(Config.LOGTAG, "ignoring read callback. mActivityPaused=" + Boolean.toString(mActivityPaused));
+            Log.d(Config.LOGTAG, "ignoring read callback. mActivityPaused=" + mActivityPaused);
         }
     }
 

src/main/java/eu/siacs/conversations/ui/ConversationsOverviewFragment.java

@@ -33,14 +33,9 @@ import android.app.Activity;
 import android.app.AlertDialog;
 import android.app.Fragment;
 import android.content.Intent;
-import androidx.databinding.DataBindingUtil;
 import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.os.Bundle;
-import com.google.android.material.snackbar.Snackbar;
-import androidx.recyclerview.widget.LinearLayoutManager;
-import androidx.recyclerview.widget.RecyclerView;
-import androidx.recyclerview.widget.ItemTouchHelper;
 import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.Menu;
@@ -50,6 +45,12 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Toast;
 
+import androidx.databinding.DataBindingUtil;
+import androidx.recyclerview.widget.ItemTouchHelper;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+
+import com.google.android.material.snackbar.Snackbar;
 import com.google.common.collect.Collections2;
 
 import java.util.ArrayList;
@@ -88,9 +89,9 @@ public class ConversationsOverviewFragment extends XmppFragment {
 	private ConversationAdapter conversationsAdapter;
 	private XmppActivity activity;
 	private float mSwipeEscapeVelocity = 0f;
-	private PendingActionHelper pendingActionHelper = new PendingActionHelper();
+	private final PendingActionHelper pendingActionHelper = new PendingActionHelper();
 
-	private ItemTouchHelper.SimpleCallback callback = new ItemTouchHelper.SimpleCallback(0,LEFT|RIGHT) {
+	private final ItemTouchHelper.SimpleCallback callback = new ItemTouchHelper.SimpleCallback(0,LEFT|RIGHT) {
 		@Override
 		public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
 			//todo maybe we can manually changing the position of the conversation

src/main/java/eu/siacs/conversations/ui/CreatePrivateGroupChatDialog.java

@@ -2,13 +2,14 @@ package eu.siacs.conversations.ui;
 
 import android.app.Dialog;
 import android.content.Context;
-import androidx.databinding.DataBindingUtil;
 import android.os.Bundle;
-import androidx.annotation.NonNull;
-import androidx.fragment.app.DialogFragment;
-import androidx.appcompat.app.AlertDialog;
 import android.widget.Spinner;
 
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AlertDialog;
+import androidx.databinding.DataBindingUtil;
+import androidx.fragment.app.DialogFragment;
+
 import java.util.ArrayList;
 import java.util.List;
 

src/main/java/eu/siacs/conversations/ui/CreatePublicChannelDialog.java

@@ -4,11 +4,7 @@ import android.app.Activity;
 import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
-import androidx.databinding.DataBindingUtil;
 import android.os.Bundle;
-import androidx.annotation.NonNull;
-import androidx.fragment.app.DialogFragment;
-import androidx.appcompat.app.AlertDialog;
 import android.text.Editable;
 import android.text.TextUtils;
 import android.text.TextWatcher;
@@ -16,6 +12,11 @@ import android.view.View;
 import android.widget.AdapterView;
 import android.widget.Button;
 
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AlertDialog;
+import androidx.databinding.DataBindingUtil;
+import androidx.fragment.app.DialogFragment;
+
 import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -29,8 +30,8 @@ import eu.siacs.conversations.ui.adapter.KnownHostsAdapter;
 import eu.siacs.conversations.ui.interfaces.OnBackendConnected;
 import eu.siacs.conversations.ui.util.DelayedHintHelper;
 import eu.siacs.conversations.utils.CryptoHelper;
-import eu.siacs.conversations.xmpp.XmppConnection;
 import eu.siacs.conversations.xmpp.Jid;
+import eu.siacs.conversations.xmpp.XmppConnection;
 
 public class CreatePublicChannelDialog extends DialogFragment implements OnBackendConnected {
 

src/main/java/eu/siacs/conversations/ui/EditAccountActivity.java

@@ -6,7 +6,6 @@ import android.content.ActivityNotFoundException;
 import android.content.Intent;
 import android.content.IntentSender;
 import android.content.SharedPreferences;
-import androidx.databinding.DataBindingUtil;
 import android.graphics.Bitmap;
 import android.net.Uri;
 import android.os.Build;
@@ -16,11 +15,6 @@ import android.preference.PreferenceManager;
 import android.provider.Settings;
 import android.security.KeyChain;
 import android.security.KeyChainAliasCallback;
-import com.google.android.material.textfield.TextInputLayout;
-import androidx.appcompat.app.ActionBar;
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.app.AlertDialog.Builder;
-import androidx.appcompat.widget.Toolbar;
 import android.text.Editable;
 import android.text.TextUtils;
 import android.text.TextWatcher;
@@ -34,6 +28,12 @@ import android.widget.EditText;
 import android.widget.ImageView;
 import android.widget.Toast;
 
+import androidx.appcompat.app.ActionBar;
+import androidx.appcompat.app.AlertDialog;
+import androidx.appcompat.app.AlertDialog.Builder;
+import androidx.databinding.DataBindingUtil;
+
+import com.google.android.material.textfield.TextInputLayout;
 import com.google.common.base.CharMatcher;
 
 import org.openintents.openpgp.util.OpenPgpUtils;
@@ -317,7 +317,7 @@ public class EditAccountActivity extends OmemoActivity implements OnAccountUpdat
 
         }
     };
-    private View.OnFocusChangeListener mEditTextFocusListener = new View.OnFocusChangeListener() {
+    private final View.OnFocusChangeListener mEditTextFocusListener = new View.OnFocusChangeListener() {
         @Override
         public void onFocusChange(View view, boolean b) {
             EditText et = (EditText) view;
@@ -597,7 +597,7 @@ public class EditAccountActivity extends OmemoActivity implements OnAccountUpdat
             this.mSavedInstanceInit = savedInstanceState.getBoolean("initMode", false);
         }
         this.binding = DataBindingUtil.setContentView(this, R.layout.activity_edit_account);
-        setSupportActionBar((Toolbar) binding.toolbar);
+        setSupportActionBar(binding.toolbar);
         binding.accountJid.addTextChangedListener(this.mTextWatcher);
         binding.accountJid.setOnFocusChangeListener(this.mEditTextFocusListener);
         this.binding.accountPassword.addTextChangedListener(this.mTextWatcher);

src/main/java/eu/siacs/conversations/ui/EnterJidDialog.java

@@ -2,16 +2,17 @@ package eu.siacs.conversations.ui;
 
 import android.app.Activity;
 import android.app.Dialog;
-import androidx.databinding.DataBindingUtil;
 import android.os.Bundle;
-import androidx.annotation.NonNull;
-import androidx.fragment.app.DialogFragment;
-import androidx.appcompat.app.AlertDialog;
 import android.text.Editable;
 import android.text.TextWatcher;
 import android.view.View;
 import android.widget.ArrayAdapter;
 
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AlertDialog;
+import androidx.databinding.DataBindingUtil;
+import androidx.fragment.app.DialogFragment;
+
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;

src/main/java/eu/siacs/conversations/ui/JoinConferenceDialog.java

@@ -2,18 +2,18 @@ package eu.siacs.conversations.ui;
 
 import android.app.Activity;
 import android.app.Dialog;
-import androidx.databinding.DataBindingUtil;
-import androidx.annotation.NonNull;
-import com.google.android.material.textfield.TextInputLayout;
-import androidx.fragment.app.DialogFragment;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.os.Bundle;
-import androidx.appcompat.app.AlertDialog;
-import android.view.KeyEvent;
 import android.widget.AutoCompleteTextView;
 import android.widget.Spinner;
-import android.widget.TextView;
+
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AlertDialog;
+import androidx.databinding.DataBindingUtil;
+import androidx.fragment.app.DialogFragment;
+
+import com.google.android.material.textfield.TextInputLayout;
 
 import java.util.ArrayList;
 import java.util.Collection;

src/main/java/eu/siacs/conversations/ui/LocationActivity.java

@@ -14,11 +14,12 @@ import android.os.Build;
 import android.os.Bundle;
 import android.preference.PreferenceManager;
 import android.provider.Settings;
-import androidx.annotation.BoolRes;
-import androidx.annotation.NonNull;
 import android.util.Log;
 import android.view.MenuItem;
 
+import androidx.annotation.BoolRes;
+import androidx.annotation.NonNull;
+
 import org.osmdroid.api.IGeoPoint;
 import org.osmdroid.api.IMapController;
 import org.osmdroid.config.Configuration;

src/main/java/eu/siacs/conversations/ui/MediaBrowserActivity.java

@@ -2,18 +2,17 @@ package eu.siacs.conversations.ui;
 
 import android.content.Context;
 import android.content.Intent;
-import androidx.databinding.DataBindingUtil;
 import android.os.Bundle;
-import androidx.appcompat.widget.Toolbar;
+
+import androidx.databinding.DataBindingUtil;
 
 import java.util.List;
 
 import eu.siacs.conversations.R;
+import eu.siacs.conversations.databinding.ActivityMediaBrowserBinding;
 import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.entities.Contact;
 import eu.siacs.conversations.entities.Conversation;
-
-import eu.siacs.conversations.databinding.ActivityMediaBrowserBinding;
 import eu.siacs.conversations.ui.adapter.MediaAdapter;
 import eu.siacs.conversations.ui.interfaces.OnMediaLoaded;
 import eu.siacs.conversations.ui.util.Attachment;
@@ -30,7 +29,7 @@ public class MediaBrowserActivity extends XmppActivity implements OnMediaLoaded
     protected void onCreate(final Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         this.binding = DataBindingUtil.setContentView(this,R.layout.activity_media_browser);
-        setSupportActionBar((Toolbar) binding.toolbar);
+        setSupportActionBar(binding.toolbar);
         configureActionBar(getSupportActionBar());
         mMediaAdapter = new MediaAdapter(this, R.dimen.media_size);
         this.binding.media.setAdapter(mMediaAdapter);

src/main/java/eu/siacs/conversations/ui/MemorizingActivity.java

@@ -28,9 +28,8 @@ import android.content.DialogInterface;
 import android.content.DialogInterface.OnCancelListener;
 import android.content.DialogInterface.OnClickListener;
 import android.content.Intent;
-import android.content.SharedPreferences;
 import android.os.Bundle;
-import android.preference.PreferenceManager;
+
 import androidx.appcompat.app.AlertDialog;
 import androidx.appcompat.app.AppCompatActivity;
 

src/main/java/eu/siacs/conversations/ui/MucUsersActivity.java

@@ -2,9 +2,7 @@ package eu.siacs.conversations.ui;
 
 import android.content.Context;
 import android.content.Intent;
-import androidx.databinding.DataBindingUtil;
 import android.os.Bundle;
-import androidx.appcompat.widget.Toolbar;
 import android.text.Editable;
 import android.text.TextUtils;
 import android.text.TextWatcher;
@@ -15,6 +13,8 @@ import android.view.inputmethod.InputMethodManager;
 import android.widget.EditText;
 import android.widget.Toast;
 
+import androidx.databinding.DataBindingUtil;
+
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Locale;
@@ -90,7 +90,7 @@ public class MucUsersActivity extends XmppActivity implements XmppConnectionServ
     protected void onCreate(final Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         ActivityMucUsersBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_muc_users);
-        setSupportActionBar((Toolbar) binding.toolbar);
+        setSupportActionBar(binding.toolbar);
         configureActionBar(getSupportActionBar(), true);
         this.userAdapter = new UserAdapter(getPreferences().getBoolean("advanced_muc_mode", false));
         binding.list.setAdapter(this.userAdapter);

src/main/java/eu/siacs/conversations/ui/OmemoActivity.java

@@ -1,17 +1,16 @@
 package eu.siacs.conversations.ui;
 
-import androidx.databinding.DataBindingUtil;
-
-import androidx.appcompat.app.AlertDialog;
 import android.content.Intent;
 import android.view.ContextMenu;
 import android.view.MenuItem;
 import android.view.View;
 import android.widget.CompoundButton;
-
 import android.widget.LinearLayout;
 import android.widget.Toast;
 
+import androidx.appcompat.app.AlertDialog;
+import androidx.databinding.DataBindingUtil;
+
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.R;
 import eu.siacs.conversations.crypto.axolotl.FingerprintStatus;
@@ -205,7 +204,7 @@ public abstract class OmemoActivity extends XmppActivity {
 	}
 
 	@Override
-	public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
+	public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
 		ScanActivity.onRequestPermissionResult(this, requestCode, grantResults);
 	}
 }

src/main/java/eu/siacs/conversations/ui/PublishGroupChatProfilePictureActivity.java

@@ -30,16 +30,16 @@
 package eu.siacs.conversations.ui;
 
 import android.content.Intent;
-import androidx.databinding.DataBindingUtil;
 import android.graphics.Bitmap;
 import android.net.Uri;
 import android.os.Bundle;
-import androidx.annotation.StringRes;
-import androidx.appcompat.widget.Toolbar;
 import android.util.Log;
 import android.view.View;
 import android.widget.Toast;
 
+import androidx.annotation.StringRes;
+import androidx.databinding.DataBindingUtil;
+
 import com.theartofdev.edmodo.cropper.CropImage;
 
 import eu.siacs.conversations.Config;
@@ -91,7 +91,7 @@ public class PublishGroupChatProfilePictureActivity extends XmppActivity impleme
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         this.binding = DataBindingUtil.setContentView(this, R.layout.activity_publish_profile_picture);
-        setSupportActionBar((Toolbar) this.binding.toolbar);
+        setSupportActionBar(this.binding.toolbar);
         configureActionBar(getSupportActionBar());
         this.binding.cancelButton.setOnClickListener((v) -> this.finish());
         this.binding.secondaryHint.setVisibility(View.GONE);

src/main/java/eu/siacs/conversations/ui/PublishProfilePictureActivity.java

@@ -6,7 +6,6 @@ import android.graphics.Bitmap;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
-import androidx.annotation.StringRes;
 import android.util.Log;
 import android.view.View;
 import android.view.View.OnLongClickListener;
@@ -15,6 +14,8 @@ import android.widget.ImageView;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.annotation.StringRes;
+
 import com.theartofdev.edmodo.cropper.CropImage;
 
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -40,8 +41,8 @@ public class PublishProfilePictureActivity extends XmppActivity implements XmppC
     private Account account;
     private boolean support = false;
     private boolean publishing = false;
-    private AtomicBoolean handledExternalUri = new AtomicBoolean(false);
+    private final AtomicBoolean handledExternalUri = new AtomicBoolean(false);
-    private OnLongClickListener backToDefaultListener = new OnLongClickListener() {
+    private final OnLongClickListener backToDefaultListener = new OnLongClickListener() {
 
         @Override
         public boolean onLongClick(View v) {

src/main/java/eu/siacs/conversations/ui/RecordingActivity.java

@@ -3,7 +3,6 @@ package eu.siacs.conversations.ui;
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
-import androidx.databinding.DataBindingUtil;
 import android.media.MediaRecorder;
 import android.net.Uri;
 import android.os.Bundle;
@@ -15,6 +14,8 @@ import android.view.View;
 import android.view.WindowManager;
 import android.widget.Toast;
 
+import androidx.databinding.DataBindingUtil;
+
 import java.io.File;
 import java.io.IOException;
 import java.text.SimpleDateFormat;
@@ -39,10 +40,10 @@ public class RecordingActivity extends Activity implements View.OnClickListener
     private MediaRecorder mRecorder;
     private long mStartTime = 0;
 
-    private CountDownLatch outputFileWrittenLatch = new CountDownLatch(1);
+    private final CountDownLatch outputFileWrittenLatch = new CountDownLatch(1);
 
-    private Handler mHandler = new Handler();
+    private final Handler mHandler = new Handler();
-    private Runnable mTickExecutor = new Runnable() {
+    private final Runnable mTickExecutor = new Runnable() {
         @Override
         public void run() {
             tick();

src/main/java/eu/siacs/conversations/ui/RtpSessionActivity.java

@@ -7,15 +7,11 @@ import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.Intent;
 import android.content.pm.PackageManager;
-import androidx.databinding.DataBindingUtil;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.PowerManager;
 import android.os.SystemClock;
-import androidx.annotation.NonNull;
-import androidx.annotation.RequiresApi;
-import androidx.annotation.StringRes;
 import android.util.Log;
 import android.util.Rational;
 import android.view.Menu;
@@ -24,6 +20,11 @@ import android.view.View;
 import android.view.WindowManager;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.RequiresApi;
+import androidx.annotation.StringRes;
+import androidx.databinding.DataBindingUtil;
+
 import com.google.common.base.Optional;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Throwables;
@@ -55,12 +56,12 @@ import eu.siacs.conversations.ui.util.MainThreadExecutor;
 import eu.siacs.conversations.utils.PermissionUtils;
 import eu.siacs.conversations.utils.TimeFrameUtils;
 import eu.siacs.conversations.xml.Namespace;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.jingle.AbstractJingleConnection;
 import eu.siacs.conversations.xmpp.jingle.JingleConnectionManager;
 import eu.siacs.conversations.xmpp.jingle.JingleRtpConnection;
 import eu.siacs.conversations.xmpp.jingle.Media;
 import eu.siacs.conversations.xmpp.jingle.RtpEndUserState;
-import eu.siacs.conversations.xmpp.Jid;
 
 import static eu.siacs.conversations.utils.PermissionUtils.getFirstDenied;
 import static java.util.Arrays.asList;
@@ -99,8 +100,8 @@ public class RtpSessionActivity extends XmppActivity implements XmppConnectionSe
     private ActivityRtpSessionBinding binding;
     private PowerManager.WakeLock mProximityWakeLock;
 
-    private Handler mHandler = new Handler();
+    private final Handler mHandler = new Handler();
-    private Runnable mTickExecutor = new Runnable() {
+    private final Runnable mTickExecutor = new Runnable() {
         @Override
         public void run() {
             updateCallDuration();

src/main/java/eu/siacs/conversations/ui/ScanActivity.java

@@ -17,18 +17,6 @@
 
 package eu.siacs.conversations.ui;
 
-import java.util.EnumMap;
-import java.util.Map;
-
-import com.google.zxing.BinaryBitmap;
-import com.google.zxing.DecodeHintType;
-import com.google.zxing.PlanarYUVLuminanceSource;
-import com.google.zxing.ReaderException;
-import com.google.zxing.Result;
-import com.google.zxing.ResultPointCallback;
-import com.google.zxing.common.HybridBinarizer;
-import com.google.zxing.qrcode.QRCodeReader;
-
 import android.Manifest;
 import android.app.Activity;
 import android.content.Context;
@@ -45,8 +33,6 @@ import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.Process;
 import android.os.Vibrator;
-import androidx.core.app.ActivityCompat;
-import androidx.core.content.ContextCompat;
 import android.util.Log;
 import android.view.KeyEvent;
 import android.view.Surface;
@@ -56,6 +42,21 @@ import android.view.View;
 import android.view.WindowManager;
 import android.widget.Toast;
 
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
+
+import com.google.zxing.BinaryBitmap;
+import com.google.zxing.DecodeHintType;
+import com.google.zxing.PlanarYUVLuminanceSource;
+import com.google.zxing.ReaderException;
+import com.google.zxing.Result;
+import com.google.zxing.ResultPointCallback;
+import com.google.zxing.common.HybridBinarizer;
+import com.google.zxing.qrcode.QRCodeReader;
+
+import java.util.EnumMap;
+import java.util.Map;
+
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.R;
 import eu.siacs.conversations.ui.service.CameraManager;
@@ -73,7 +74,7 @@ public final class ScanActivity extends Activity implements SurfaceTextureListen
 
 	private static final long VIBRATE_DURATION = 50L;
 	private static final long AUTO_FOCUS_INTERVAL_MS = 2500L;
-	private static boolean DISABLE_CONTINUOUS_AUTOFOCUS = Build.MODEL.equals("GT-I9100") // Galaxy S2
+	private static final boolean DISABLE_CONTINUOUS_AUTOFOCUS = Build.MODEL.equals("GT-I9100") // Galaxy S2
 			|| Build.MODEL.equals("SGH-T989") // Galaxy S2
 			|| Build.MODEL.equals("SGH-T989D") // Galaxy S2 X
 			|| Build.MODEL.equals("SAMSUNG-SGH-I727") // Galaxy S2 Skyrocket

src/main/java/eu/siacs/conversations/ui/SearchActivity.java

@@ -30,9 +30,7 @@
 package eu.siacs.conversations.ui;
 
 import android.content.Intent;
-import androidx.databinding.DataBindingUtil;
 import android.os.Bundle;
-import androidx.appcompat.widget.Toolbar;
 import android.text.Editable;
 import android.text.InputType;
 import android.text.TextWatcher;
@@ -44,6 +42,8 @@ import android.view.View;
 import android.widget.AdapterView;
 import android.widget.EditText;
 
+import androidx.databinding.DataBindingUtil;
+
 import com.google.common.base.Strings;
 
 import java.lang.ref.WeakReference;
@@ -61,10 +61,10 @@ import eu.siacs.conversations.ui.adapter.MessageAdapter;
 import eu.siacs.conversations.ui.interfaces.OnSearchResultsAvailable;
 import eu.siacs.conversations.ui.util.ChangeWatcher;
 import eu.siacs.conversations.ui.util.DateSeparator;
-import eu.siacs.conversations.ui.util.StyledAttributes;
 import eu.siacs.conversations.ui.util.ListViewUtils;
 import eu.siacs.conversations.ui.util.PendingItem;
 import eu.siacs.conversations.ui.util.ShareUtil;
+import eu.siacs.conversations.ui.util.StyledAttributes;
 import eu.siacs.conversations.utils.FtsUtils;
 import eu.siacs.conversations.utils.MessageUtils;
 
@@ -95,7 +95,7 @@ public class SearchActivity extends XmppActivity implements TextWatcher, OnSearc
 		}
 		super.onCreate(bundle);
 		this.binding = DataBindingUtil.setContentView(this, R.layout.activity_search);
-		setSupportActionBar((Toolbar) this.binding.toolbar);
+		setSupportActionBar(this.binding.toolbar);
 		configureActionBar(getSupportActionBar());
 		this.messageListAdapter = new MessageAdapter(this, this.messages);
 		this.messageListAdapter.setOnContactPictureClicked(this);

src/main/java/eu/siacs/conversations/ui/SettingsActivity.java

@@ -1,19 +1,15 @@
 package eu.siacs.conversations.ui;
 
-import android.preference.CheckBoxPreference;
-import androidx.annotation.NonNull;
-import androidx.core.content.ContextCompat;
-import androidx.appcompat.app.AlertDialog;
 import android.app.FragmentManager;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
 import android.content.pm.PackageManager;
-
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
+import android.preference.CheckBoxPreference;
 import android.preference.ListPreference;
 import android.preference.Preference;
 import android.preference.PreferenceCategory;
@@ -23,6 +19,10 @@ import android.provider.MediaStore;
 import android.util.Log;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AlertDialog;
+import androidx.core.content.ContextCompat;
+
 import java.io.File;
 import java.security.KeyStoreException;
 import java.util.ArrayList;
@@ -188,11 +188,7 @@ public class SettingsActivity extends XmppActivity implements
 							} else if (selectedItems.contains(indexSelected)) {
 								selectedItems.remove(Integer.valueOf(indexSelected));
 							}
-							if (selectedItems.size() > 0)
+                            ((AlertDialog) dialog).getButton(DialogInterface.BUTTON_POSITIVE).setEnabled(selectedItems.size() > 0);
-								((AlertDialog) dialog).getButton(DialogInterface.BUTTON_POSITIVE).setEnabled(true);
-							else {
-								((AlertDialog) dialog).getButton(DialogInterface.BUTTON_POSITIVE).setEnabled(false);
-							}
 						});
 
 				dialogBuilder.setPositiveButton(

src/main/java/eu/siacs/conversations/ui/ShareLocationActivity.java

@@ -3,16 +3,17 @@ package eu.siacs.conversations.ui;
 import android.Manifest;
 import android.content.Intent;
 import android.content.pm.PackageManager;
-import androidx.databinding.DataBindingUtil;
 import android.location.Location;
 import android.location.LocationListener;
 import android.os.Build;
 import android.os.Bundle;
-import androidx.annotation.NonNull;
-import com.google.android.material.snackbar.Snackbar;
-import androidx.appcompat.widget.Toolbar;
 import android.view.View;
 
+import androidx.annotation.NonNull;
+import androidx.databinding.DataBindingUtil;
+
+import com.google.android.material.snackbar.Snackbar;
+
 import org.osmdroid.api.IGeoPoint;
 import org.osmdroid.util.GeoPoint;
 
@@ -54,7 +55,7 @@ public class ShareLocationActivity extends LocationActivity implements LocationL
 		super.onCreate(savedInstanceState);
 
 		this.binding = DataBindingUtil.setContentView(this,R.layout.activity_share_location);
-		setSupportActionBar((Toolbar) binding.toolbar);
+		setSupportActionBar(binding.toolbar);
 		configureActionBar(getSupportActionBar());
 		setupMapView(binding.map, LocationProvider.getGeoPoint(this));
 

src/main/java/eu/siacs/conversations/ui/ShareWithActivity.java

@@ -4,13 +4,14 @@ import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.Bundle;
-import androidx.recyclerview.widget.LinearLayoutManager;
-import androidx.recyclerview.widget.RecyclerView;
 import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.widget.Toast;
 
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+
 import java.util.ArrayList;
 import java.util.List;
 
@@ -44,7 +45,7 @@ public class ShareWithActivity extends XmppActivity implements XmppConnectionSer
 
     private static final int REQUEST_START_NEW_CONVERSATION = 0x0501;
     private ConversationAdapter mAdapter;
-    private List<Conversation> mConversations = new ArrayList<>();
+    private final List<Conversation> mConversations = new ArrayList<>();
 
 
     protected void onActivityResult(int requestCode, int resultCode, final Intent data) {
@@ -63,7 +64,7 @@ public class ShareWithActivity extends XmppActivity implements XmppConnectionSer
     }
 
     @Override
-    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
+    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
         if (grantResults.length > 0)
             if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                 if (requestCode == REQUEST_STORAGE_PERMISSION) {

src/main/java/eu/siacs/conversations/ui/ShortcutActivity.java

@@ -4,16 +4,14 @@ import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
-import androidx.appcompat.app.ActionBar;
-import android.util.Log;
-import android.view.View;
 import android.view.inputmethod.InputMethodManager;
 
+import androidx.appcompat.app.ActionBar;
+
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
-import eu.siacs.conversations.Config;
 import eu.siacs.conversations.R;
 import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.entities.Contact;

src/main/java/eu/siacs/conversations/ui/ShowLocationActivity.java

@@ -5,18 +5,18 @@ import android.content.ClipData;
 import android.content.ClipboardManager;
 import android.content.ComponentName;
 import android.content.Intent;
-import androidx.databinding.DataBindingUtil;
 import android.location.Location;
 import android.location.LocationListener;
 import android.net.Uri;
 import android.os.Bundle;
-import androidx.annotation.NonNull;
-import androidx.appcompat.widget.Toolbar;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.databinding.DataBindingUtil;
+
 import org.osmdroid.util.GeoPoint;
 
 import java.util.HashMap;
@@ -48,7 +48,7 @@ public class ShowLocationActivity extends LocationActivity implements LocationLi
 		super.onCreate(savedInstanceState);
 
 		this.binding = DataBindingUtil.setContentView(this,R.layout.activity_show_location);
-		setSupportActionBar((Toolbar) binding.toolbar);
+		setSupportActionBar(binding.toolbar);
 
 		configureActionBar(getSupportActionBar());
 		setupMapView(this.binding.map, this.loc);
@@ -193,7 +193,7 @@ public class ShowLocationActivity extends LocationActivity implements LocationLi
 	private void startNavigation() {
 		startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(
 				"google.navigation:q=" +
-						String.valueOf(this.loc.getLatitude()) + "," + String.valueOf(this.loc.getLongitude())
+						this.loc.getLatitude() + "," + this.loc.getLongitude()
 		)));
 	}
 

src/main/java/eu/siacs/conversations/ui/StartConversationActivity.java

@@ -9,22 +9,9 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
-import androidx.databinding.DataBindingUtil;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-import com.google.android.material.textfield.TextInputLayout;
-import androidx.fragment.app.Fragment;
-import androidx.fragment.app.FragmentManager;
-import androidx.fragment.app.FragmentTransaction;
-import androidx.viewpager.widget.PagerAdapter;
-import androidx.viewpager.widget.ViewPager;
-import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
-import androidx.appcompat.app.ActionBar;
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.widget.Toolbar;
 import android.text.Editable;
 import android.text.Html;
 import android.text.TextWatcher;
@@ -50,6 +37,20 @@ import android.widget.Spinner;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.ActionBar;
+import androidx.appcompat.app.AlertDialog;
+import androidx.databinding.DataBindingUtil;
+import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentManager;
+import androidx.fragment.app.FragmentTransaction;
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
+import androidx.viewpager.widget.PagerAdapter;
+import androidx.viewpager.widget.ViewPager;
+
+import com.google.android.material.textfield.TextInputLayout;
+
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -77,9 +78,9 @@ import eu.siacs.conversations.ui.util.SoftKeyboardUtils;
 import eu.siacs.conversations.ui.widget.SwipeRefreshListFragment;
 import eu.siacs.conversations.utils.AccountUtils;
 import eu.siacs.conversations.utils.XmppUri;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 import eu.siacs.conversations.xmpp.XmppConnection;
-import eu.siacs.conversations.xmpp.Jid;
 
 public class StartConversationActivity extends XmppActivity implements XmppConnectionService.OnConversationUpdate, OnRosterUpdate, OnUpdateBlocklist, CreatePrivateGroupChatDialog.CreateConferenceDialogListener, JoinConferenceDialog.JoinConferenceDialogListener, SwipeRefreshLayout.OnRefreshListener, CreatePublicChannelDialog.CreatePublicChannelDialogListener {
 
@@ -261,8 +262,7 @@ public class StartConversationActivity extends XmppActivity implements XmppConne
 	public void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 		this.binding = DataBindingUtil.setContentView(this, R.layout.activity_start_conversation);
-		Toolbar toolbar = (Toolbar) binding.toolbar;
+		setSupportActionBar(binding.toolbar);
-		setSupportActionBar(toolbar);
 		configureActionBar(getSupportActionBar());
 
 		binding.speedDial.inflate(R.menu.start_conversation_fab_submenu);
@@ -760,7 +760,7 @@ public class StartConversationActivity extends XmppActivity implements XmppConne
 	}
 
 	@Override
-	public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
+	public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
 		if (grantResults.length > 0)
 			if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
 				ScanActivity.onRequestPermissionResult(this, requestCode, grantResults);

src/main/java/eu/siacs/conversations/ui/TrustKeysActivity.java

@@ -2,10 +2,7 @@ package eu.siacs.conversations.ui;
 
 import android.app.AlertDialog;
 import android.content.Intent;
-import androidx.databinding.DataBindingUtil;
 import android.os.Bundle;
-import androidx.appcompat.app.ActionBar;
-import androidx.appcompat.widget.Toolbar;
 import android.util.Log;
 import android.view.Gravity;
 import android.view.Menu;
@@ -14,6 +11,9 @@ import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Toast;
 
+import androidx.appcompat.app.ActionBar;
+import androidx.databinding.DataBindingUtil;
+
 import org.whispersystems.libsignal.IdentityKey;
 
 import java.util.ArrayList;
@@ -37,8 +37,8 @@ import eu.siacs.conversations.entities.Message;
 import eu.siacs.conversations.utils.CryptoHelper;
 import eu.siacs.conversations.utils.IrregularUnicodeDetector;
 import eu.siacs.conversations.utils.XmppUri;
-import eu.siacs.conversations.xmpp.OnKeyStatusUpdated;
 import eu.siacs.conversations.xmpp.Jid;
+import eu.siacs.conversations.xmpp.OnKeyStatusUpdated;
 
 
 public class TrustKeysActivity extends OmemoActivity implements OnKeyStatusUpdated {
@@ -55,7 +55,7 @@ public class TrustKeysActivity extends OmemoActivity implements OnKeyStatusUpdat
 		commitTrusts();
 		finishOk(false);
 	};
-	private AtomicBoolean mUseCameraHintShown = new AtomicBoolean(false);
+	private final AtomicBoolean mUseCameraHintShown = new AtomicBoolean(false);
 	private AxolotlService.FetchStatus lastFetchReport = AxolotlService.FetchStatus.SUCCESS;
 	private Toast mUseCameraHintToast = null;
 	private ActivityTrustKeysBinding binding;
@@ -82,7 +82,7 @@ public class TrustKeysActivity extends OmemoActivity implements OnKeyStatusUpdat
 		binding.cancelButton.setOnClickListener(mCancelButtonListener);
 		binding.saveButton.setOnClickListener(mSaveButtonListener);
 
-		setSupportActionBar((Toolbar) binding.toolbar);
+		setSupportActionBar(binding.toolbar);
 		configureActionBar(getSupportActionBar());
 
 		if (savedInstanceState != null) {
@@ -151,7 +151,7 @@ public class TrustKeysActivity extends OmemoActivity implements OnKeyStatusUpdat
 			}
 		} else {
 			reloadFingerprints();
-			Log.d(Config.LOGTAG, "xmpp uri was: " + uri.getJid() + " has Fingerprints: " + Boolean.toString(uri.hasFingerprints()));
+			Log.d(Config.LOGTAG, "xmpp uri was: " + uri.getJid() + " has Fingerprints: " + uri.hasFingerprints());
 			Toast.makeText(this, R.string.barcode_does_not_contain_fingerprints_for_this_conversation, Toast.LENGTH_SHORT).show();
 		}
 		populateView();
@@ -437,7 +437,7 @@ public class TrustKeysActivity extends OmemoActivity implements OnKeyStatusUpdat
 		synchronized (this.foreignKeysToTrust) {
 			for (Jid jid : contactJids) {
 				Map<String, Boolean> fingerprints = foreignKeysToTrust.get(jid);
-				if (hasNoOtherTrustedKeys(jid) && (fingerprints == null || !fingerprints.values().contains(true))) {
+				if (hasNoOtherTrustedKeys(jid) && (fingerprints == null || !fingerprints.containsValue(true))) {
 					lock();
 					return;
 				}

src/main/java/eu/siacs/conversations/ui/UriHandlerActivity.java

@@ -7,10 +7,11 @@ import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
-import androidx.core.content.ContextCompat;
-import androidx.appcompat.app.AppCompatActivity;
 import android.widget.Toast;
 
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.core.content.ContextCompat;
+
 import com.google.common.base.Strings;
 
 import java.util.List;

src/main/java/eu/siacs/conversations/ui/XmppActivity.java

@@ -19,7 +19,6 @@ import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
 import android.content.res.Resources;
 import android.content.res.TypedArray;
-import androidx.databinding.DataBindingUtil;
 import android.graphics.Bitmap;
 import android.graphics.Color;
 import android.graphics.Point;
@@ -35,12 +34,6 @@ import android.os.IBinder;
 import android.os.PowerManager;
 import android.os.SystemClock;
 import android.preference.PreferenceManager;
-import androidx.annotation.BoolRes;
-import androidx.annotation.NonNull;
-import androidx.annotation.StringRes;
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.app.AlertDialog.Builder;
-import androidx.appcompat.app.AppCompatDelegate;
 import android.text.InputType;
 import android.util.DisplayMetrics;
 import android.util.Log;
@@ -50,6 +43,14 @@ import android.view.View;
 import android.widget.ImageView;
 import android.widget.Toast;
 
+import androidx.annotation.BoolRes;
+import androidx.annotation.NonNull;
+import androidx.annotation.StringRes;
+import androidx.appcompat.app.AlertDialog;
+import androidx.appcompat.app.AlertDialog.Builder;
+import androidx.appcompat.app.AppCompatDelegate;
+import androidx.databinding.DataBindingUtil;
+
 import java.io.IOException;
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
@@ -77,9 +78,9 @@ import eu.siacs.conversations.ui.util.SoftKeyboardUtils;
 import eu.siacs.conversations.utils.AccountUtils;
 import eu.siacs.conversations.utils.ExceptionHelper;
 import eu.siacs.conversations.utils.ThemeHelper;
+import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.OnKeyStatusUpdated;
 import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
-import eu.siacs.conversations.xmpp.Jid;
 
 public abstract class XmppActivity extends ActionBarActivity {
 
@@ -119,12 +120,12 @@ public abstract class XmppActivity extends ActionBarActivity {
     };
     private DisplayMetrics metrics;
     private long mLastUiRefresh = 0;
-    private Handler mRefreshUiHandler = new Handler();
+    private final Handler mRefreshUiHandler = new Handler();
-    private Runnable mRefreshUiRunnable = () -> {
+    private final Runnable mRefreshUiRunnable = () -> {
         mLastUiRefresh = SystemClock.elapsedRealtime();
         refreshUiReal();
     };
-    private UiCallback<Conversation> adhocCallback = new UiCallback<Conversation>() {
+    private final UiCallback<Conversation> adhocCallback = new UiCallback<Conversation>() {
         @Override
         public void success(final Conversation conversation) {
             runOnUiThread(() -> {
@@ -913,7 +914,7 @@ public abstract class XmppActivity extends ActionBarActivity {
 
     public static class ConferenceInvite {
         private String uuid;
-        private List<Jid> jids = new ArrayList<>();
+        private final List<Jid> jids = new ArrayList<>();
 
         public static ConferenceInvite parse(Intent data) {
             ConferenceInvite invite = new ConferenceInvite();

src/main/java/eu/siacs/conversations/ui/adapter/AccountAdapter.java

@@ -1,13 +1,13 @@
 package eu.siacs.conversations.ui.adapter;
 
-import androidx.databinding.DataBindingUtil;
-
-import androidx.annotation.NonNull;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ArrayAdapter;
 
+import androidx.annotation.NonNull;
+import androidx.databinding.DataBindingUtil;
+
 import java.util.List;
 
 import eu.siacs.conversations.Config;
@@ -20,8 +20,8 @@ import eu.siacs.conversations.ui.util.StyledAttributes;
 
 public class AccountAdapter extends ArrayAdapter<Account> {
 
-    private XmppActivity activity;
+    private final XmppActivity activity;
-    private boolean showStateButton;
+    private final boolean showStateButton;
 
     public AccountAdapter(XmppActivity activity, List<Account> objects, boolean showStateButton) {
         super(activity, 0, objects);

src/main/java/eu/siacs/conversations/ui/adapter/ChannelSearchResultAdapter.java

@@ -1,17 +1,18 @@
 package eu.siacs.conversations.ui.adapter;
 
 import android.app.Activity;
-import androidx.databinding.DataBindingUtil;
-import androidx.annotation.NonNull;
-import androidx.recyclerview.widget.ListAdapter;
-import androidx.recyclerview.widget.DiffUtil;
-import androidx.recyclerview.widget.RecyclerView;
 import android.text.TextUtils;
 import android.view.ContextMenu;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
+import androidx.annotation.NonNull;
+import androidx.databinding.DataBindingUtil;
+import androidx.recyclerview.widget.DiffUtil;
+import androidx.recyclerview.widget.ListAdapter;
+import androidx.recyclerview.widget.RecyclerView;
+
 import java.util.Locale;
 
 import eu.siacs.conversations.R;

src/main/java/eu/siacs/conversations/ui/adapter/ConversationAdapter.java

@@ -1,14 +1,15 @@
 package eu.siacs.conversations.ui.adapter;
 
-import androidx.databinding.DataBindingUtil;
 import android.graphics.Typeface;
-import androidx.annotation.NonNull;
-import androidx.recyclerview.widget.RecyclerView;
 import android.util.Pair;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
+import androidx.annotation.NonNull;
+import androidx.databinding.DataBindingUtil;
+import androidx.recyclerview.widget.RecyclerView;
+
 import com.google.common.base.Optional;
 
 import java.util.List;
@@ -25,13 +26,13 @@ import eu.siacs.conversations.ui.util.StyledAttributes;
 import eu.siacs.conversations.utils.EmojiWrapper;
 import eu.siacs.conversations.utils.IrregularUnicodeDetector;
 import eu.siacs.conversations.utils.UIHelper;
-import eu.siacs.conversations.xmpp.jingle.OngoingRtpSession;
 import eu.siacs.conversations.xmpp.Jid;
+import eu.siacs.conversations.xmpp.jingle.OngoingRtpSession;
 
 public class ConversationAdapter extends RecyclerView.Adapter<ConversationAdapter.ConversationViewHolder> {
 
-    private XmppActivity activity;
+    private final XmppActivity activity;
-    private List<Conversation> conversations;
+    private final List<Conversation> conversations;
     private OnConversationClickListener listener;
 
     public ConversationAdapter(XmppActivity activity, List<Conversation> conversations) {

src/main/java/eu/siacs/conversations/ui/adapter/KnownHostsAdapter.java

@@ -1,10 +1,11 @@
 package eu.siacs.conversations.ui.adapter;
 
 import android.content.Context;
-import androidx.annotation.NonNull;
 import android.widget.ArrayAdapter;
 import android.widget.Filter;
 
+import androidx.annotation.NonNull;
+
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
@@ -15,10 +16,10 @@ import eu.siacs.conversations.Config;
 
 public class KnownHostsAdapter extends ArrayAdapter<String> {
 
-    private static Pattern E164_PATTERN = Pattern.compile("^\\+[1-9]\\d{1,14}$");
+    private static final Pattern E164_PATTERN = Pattern.compile("^\\+[1-9]\\d{1,14}$");
 
     private ArrayList<String> domains;
-    private Filter domainFilter = new Filter() {
+    private final Filter domainFilter = new Filter() {
 
         @Override
         protected FilterResults performFiltering(CharSequence constraint) {

src/main/java/eu/siacs/conversations/ui/adapter/ListItemAdapter.java

@@ -1,7 +1,6 @@
 package eu.siacs.conversations.ui.adapter;
 
 import android.content.SharedPreferences;
-import androidx.databinding.DataBindingUtil;
 import android.preference.PreferenceManager;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -10,6 +9,8 @@ import android.widget.ArrayAdapter;
 import android.widget.ImageView;
 import android.widget.TextView;
 
+import androidx.databinding.DataBindingUtil;
+
 import com.wefika.flowlayout.FlowLayout;
 
 import java.util.List;
@@ -30,7 +31,7 @@ public class ListItemAdapter extends ArrayAdapter<ListItem> {
 	protected XmppActivity activity;
 	private boolean showDynamicTags = false;
 	private OnTagClickedListener mOnTagClickedListener = null;
-	private View.OnClickListener onTagTvClick = view -> {
+	private final View.OnClickListener onTagTvClick = view -> {
 		if (view instanceof TextView && mOnTagClickedListener != null) {
 			TextView tv = (TextView) view;
 			final String tag = tv.getText().toString();

src/main/java/eu/siacs/conversations/ui/adapter/MediaAdapter.java

@@ -2,20 +2,21 @@ package eu.siacs.conversations.ui.adapter;
 
 import android.content.Context;
 import android.content.res.Resources;
-import androidx.databinding.DataBindingUtil;
 import android.graphics.Bitmap;
 import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
 import android.os.AsyncTask;
-import androidx.annotation.AttrRes;
-import androidx.annotation.DimenRes;
-import androidx.annotation.NonNull;
-import androidx.recyclerview.widget.RecyclerView;
 import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.ViewGroup;
 import android.widget.ImageView;
 
+import androidx.annotation.AttrRes;
+import androidx.annotation.DimenRes;
+import androidx.annotation.NonNull;
+import androidx.databinding.DataBindingUtil;
+import androidx.recyclerview.widget.RecyclerView;
+
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.Arrays;

src/main/java/eu/siacs/conversations/ui/adapter/MediaPreviewAdapter.java

@@ -4,19 +4,20 @@ import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.Intent;
 import android.content.res.Resources;
-import androidx.databinding.DataBindingUtil;
 import android.graphics.Bitmap;
 import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.AsyncTask;
-import androidx.annotation.NonNull;
-import androidx.recyclerview.widget.RecyclerView;
 import android.view.LayoutInflater;
 import android.view.ViewGroup;
 import android.widget.ImageView;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.databinding.DataBindingUtil;
+import androidx.recyclerview.widget.RecyclerView;
+
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.List;

src/main/java/eu/siacs/conversations/ui/adapter/MessageAdapter.java

@@ -7,8 +7,6 @@ import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
 import android.graphics.Typeface;
 import android.preference.PreferenceManager;
-import androidx.core.app.ActivityCompat;
-import androidx.core.content.ContextCompat;
 import android.text.Spannable;
 import android.text.SpannableString;
 import android.text.SpannableStringBuilder;
@@ -28,6 +26,9 @@ import android.widget.RelativeLayout;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
+
 import com.google.common.base.Strings;
 
 import java.net.URL;

src/main/java/eu/siacs/conversations/ui/adapter/PresenceTemplateAdapter.java

@@ -30,10 +30,11 @@
 package eu.siacs.conversations.ui.adapter;
 
 import android.content.Context;
-import androidx.annotation.NonNull;
 import android.widget.ArrayAdapter;
 import android.widget.Filter;
 
+import androidx.annotation.NonNull;
+
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;

src/main/java/eu/siacs/conversations/ui/adapter/UserAdapter.java

@@ -2,16 +2,17 @@ package eu.siacs.conversations.ui.adapter;
 
 import android.app.PendingIntent;
 import android.content.IntentSender;
-import androidx.databinding.DataBindingUtil;
-import androidx.annotation.NonNull;
-import androidx.recyclerview.widget.ListAdapter;
-import androidx.recyclerview.widget.DiffUtil;
-import androidx.recyclerview.widget.RecyclerView;
 import android.view.ContextMenu;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
+import androidx.annotation.NonNull;
+import androidx.databinding.DataBindingUtil;
+import androidx.recyclerview.widget.DiffUtil;
+import androidx.recyclerview.widget.ListAdapter;
+import androidx.recyclerview.widget.RecyclerView;
+
 import org.openintents.openpgp.util.OpenPgpUtils;
 
 import eu.siacs.conversations.R;

src/main/java/eu/siacs/conversations/ui/adapter/UserPreviewAdapter.java

@@ -1,14 +1,15 @@
 package eu.siacs.conversations.ui.adapter;
 
-import androidx.databinding.DataBindingUtil;
-import androidx.annotation.NonNull;
-import androidx.recyclerview.widget.ListAdapter;
-import androidx.recyclerview.widget.RecyclerView;
 import android.view.ContextMenu;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
+import androidx.annotation.NonNull;
+import androidx.databinding.DataBindingUtil;
+import androidx.recyclerview.widget.ListAdapter;
+import androidx.recyclerview.widget.RecyclerView;
+
 import eu.siacs.conversations.R;
 import eu.siacs.conversations.databinding.UserPreviewBinding;
 import eu.siacs.conversations.entities.MucOptions;

src/main/java/eu/siacs/conversations/ui/forms/FormBooleanFieldWrapper.java

@@ -16,7 +16,7 @@ public class FormBooleanFieldWrapper extends FormFieldWrapper {
 
 	protected FormBooleanFieldWrapper(Context context, Field field) {
 		super(context, field);
-		checkBox = (CheckBox) view.findViewById(R.id.field);
+		checkBox = view.findViewById(R.id.field);
 		checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
 			@Override
 			public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
@@ -28,7 +28,7 @@ public class FormBooleanFieldWrapper extends FormFieldWrapper {
 
 	@Override
 	protected void setLabel(String label, boolean required) {
-		CheckBox checkBox = (CheckBox) view.findViewById(R.id.field);
+		CheckBox checkBox = view.findViewById(R.id.field);
 		checkBox.setText(createSpannableLabelString(label, required));
 	}
 

src/main/java/eu/siacs/conversations/ui/forms/FormJidSingleFieldWrapper.java

@@ -6,8 +6,8 @@ import android.text.InputType;
 import java.util.List;
 
 import eu.siacs.conversations.R;
-import eu.siacs.conversations.xmpp.forms.Field;
 import eu.siacs.conversations.xmpp.Jid;
+import eu.siacs.conversations.xmpp.forms.Field;
 
 public class FormJidSingleFieldWrapper extends FormTextFieldWrapper {
 
@@ -34,7 +34,7 @@ public class FormJidSingleFieldWrapper extends FormTextFieldWrapper {
 
 	@Override
 	protected void setValues(List<String> values) {
-		StringBuilder builder = new StringBuilder("");
+		StringBuilder builder = new StringBuilder();
 		for(String value : values) {
 			builder.append(value);
 		}

src/main/java/eu/siacs/conversations/ui/forms/FormTextFieldWrapper.java

@@ -19,7 +19,7 @@ public class FormTextFieldWrapper extends FormFieldWrapper {
 
 	protected FormTextFieldWrapper(Context context, Field field) {
 		super(context, field);
-		editText = (EditText) view.findViewById(R.id.field);
+		editText = view.findViewById(R.id.field);
 		editText.setSingleLine(!"text-multi".equals(field.getType()));
 		if ("text-private".equals(field.getType())) {
 			editText.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
@@ -43,7 +43,7 @@ public class FormTextFieldWrapper extends FormFieldWrapper {
 
 	@Override
 	protected void setLabel(String label, boolean required) {
-		TextView textView = (TextView) view.findViewById(R.id.label);
+		TextView textView = view.findViewById(R.id.label);
 		textView.setText(createSpannableLabelString(label, required));
 	}
 
@@ -64,7 +64,7 @@ public class FormTextFieldWrapper extends FormFieldWrapper {
 
 	@Override
 	protected void setValues(List<String> values) {
-		StringBuilder builder = new StringBuilder("");
+		StringBuilder builder = new StringBuilder();
 		for(int i = 0; i < values.size(); ++i) {
 			builder.append(values.get(i));
 			if (i < values.size() - 1 && "text-multi".equals(field.getType())) {

src/main/java/eu/siacs/conversations/ui/service/AudioPlayer.java

@@ -12,8 +12,6 @@ import android.media.AudioManager;
 import android.os.Build;
 import android.os.Handler;
 import android.os.PowerManager;
-import androidx.core.app.ActivityCompat;
-import androidx.core.content.ContextCompat;
 import android.util.Log;
 import android.view.View;
 import android.widget.ImageButton;
@@ -21,6 +19,9 @@ import android.widget.RelativeLayout;
 import android.widget.SeekBar;
 import android.widget.TextView;
 
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
+
 import java.lang.ref.WeakReference;
 import java.util.Locale;
 import java.util.concurrent.ExecutorService;