provide more detailed error toasts for http file download

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

@@ -6,6 +6,7 @@ import android.util.Log;
 
 import java.io.BufferedInputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
@@ -125,6 +126,17 @@ public class HttpDownloadConnection implements Transferable {
 		mXmppConnectionService.updateConversationUi();
 	}
 
+	private void showToastForException(Exception e) {
+		e.printStackTrace();
+		if (e instanceof java.net.UnknownHostException) {
+			mXmppConnectionService.showErrorToastInUi(R.string.download_failed_server_not_found);
+		} else if (e instanceof java.net.ConnectException) {
+			mXmppConnectionService.showErrorToastInUi(R.string.download_failed_could_not_connect);
+		} else {
+			mXmppConnectionService.showErrorToastInUi(R.string.download_failed_file_not_found);
+		}
+	}
+
 	private class FileSizeChecker implements Runnable {
 
 		private boolean interactive = false;
@@ -146,7 +158,7 @@ public class HttpDownloadConnection implements Transferable {
 			} catch (IOException e) {
 				Log.d(Config.LOGTAG, "io exception in http file size checker: " + e.getMessage());
 				if (interactive) {
-					mXmppConnectionService.showErrorToastInUi(R.string.file_not_found_on_remote_host);
+					showToastForException(e);
 				}
 				cancel();
 				return;
@@ -163,6 +175,7 @@ public class HttpDownloadConnection implements Transferable {
 		}
 
 		private long retrieveFileSize() throws IOException {
+			try {
 				Log.d(Config.LOGTAG, "retrieve file size. interactive:" + String.valueOf(interactive));
 				changeStatus(STATUS_CHECKING);
 				HttpURLConnection connection = (HttpURLConnection) mUrl.openConnection();
@@ -172,11 +185,13 @@ public class HttpDownloadConnection implements Transferable {
 				}
 				connection.connect();
 				String contentLength = connection.getHeaderField("Content-Length");
+				connection.disconnect();
 				if (contentLength == null) {
 					throw new IOException();
 				}
-			try {
 				return Long.parseLong(contentLength, 10);
+			} catch (IOException e) {
+				throw e;
 			} catch (NumberFormatException e) {
 				throw new IOException();
 			}
@@ -202,22 +217,24 @@ public class HttpDownloadConnection implements Transferable {
 				updateImageBounds();
 				finish();
 			} catch (SSLHandshakeException e) {
-				FileBackend.close(os);
 				changeStatus(STATUS_OFFER);
 			} catch (IOException e) {
-				FileBackend.close(os);
+				if (interactive) {
-				mXmppConnectionService.showErrorToastInUi(R.string.file_not_found_on_remote_host);
+					showToastForException(e);
+				}
 				cancel();
 			}
 		}
 
 		private void download()  throws IOException {
+			InputStream is = null;
+			try {
 				HttpURLConnection connection = (HttpURLConnection) mUrl.openConnection();
 				if (connection instanceof HttpsURLConnection) {
 					mHttpConnectionManager.setupTrustManager((HttpsURLConnection) connection, interactive);
 				}
 				connection.connect();
-			BufferedInputStream is = new BufferedInputStream(connection.getInputStream());
+				is = new BufferedInputStream(connection.getInputStream());
 				file.getParentFile().mkdirs();
 				file.createNewFile();
 				os = AbstractConnectionManager.createOutputStream(file, true);
@@ -231,8 +248,12 @@ public class HttpDownloadConnection implements Transferable {
 					updateProgress((int) ((((double) transmitted) / expected) * 100));
 				}
 				os.flush();
-			os.close();
+			} catch (IOException e) {
-			is.close();
+				throw e;
+			} finally {
+				FileBackend.close(os);
+				FileBackend.close(is);
+			}
 		}
 
 		private void updateImageBounds() {

src/main/res/values/strings.xml

@@ -494,11 +494,13 @@
 	<string name="none">None</string>
 	<string name="recently_used">Most recently used</string>
 	<string name="choose_quick_action">Choose quick action</string>
-	<string name="file_not_found_on_remote_host">File not found on remote server</string>
 	<string name="search_for_contacts_or_groups">Search for contacts or groups</string>
 	<string name="send_private_message">Send private message</string>
 	<string name="user_has_left_conference">%s has left the conference!</string>
 	<string name="username">Username</string>
 	<string name="username_hint">Username</string>
 	<string name="invalid_username">This is not a valid username</string>
+	<string name="download_failed_server_not_found">Download failed: Server not found</string>
+	<string name="download_failed_file_not_found">Download failed: File not found</string>
+	<string name="download_failed_could_not_connect">Download failed: Could not connect to host</string>
 </resources>