Merge pull request #27 from szaboz89/i25_lazy_socket_connection

hoegertn · web-flow · commit 62dc2d804632 · 2017-07-07T11:51:05.000+02:00
Do not open socket in main thread (#25)
diff --git a/src/main/java/de/taimos/gpsd4java/backend/GPSdEndpoint.java b/src/main/java/de/taimos/gpsd4java/backend/GPSdEndpoint.java
@@ -108,10 +108,7 @@ public GPSdEndpoint(final String server, final int port, final AbstractResultPar
 		if (resultParser == null) {
 			throw new IllegalArgumentException("resultParser can not be null!");
 		}
-		
-		this.socket = new Socket(server, port);
-		this.in = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));
-		this.out = new BufferedWriter(new OutputStreamWriter(this.socket.getOutputStream()));
+
 		this.resultParser = resultParser;
 		
 		this.daemon = daemon;
@@ -236,13 +233,16 @@ public void removeListener(final IObjectListener listener) {
 	 */
 	private <T extends IGPSObject> T syncCommand(final String command, final Class<T> responseClass) throws IOException {
 		synchronized (this.asyncMutex) {
-			this.out.write(command + "\n");
-			this.out.flush();
+			if (out != null) {
+				this.out.write(command + "\n");
+				this.out.flush();
+			}
 			if (responseClass == WatchObject.class) {
 				lastWatch = command;
 			}
 			while (true) {
 				// wait for awaited message
+				// FIXME possible infinite loop if expected result arrives but new result overrides expected result before getting to this point.
 				final IGPSObject result = this.waitForResult();
 				if ((result == null) || result.getClass().equals(responseClass)) {
 					return responseClass.cast(result);
@@ -254,7 +254,6 @@ private <T extends IGPSObject> T syncCommand(final String command, final Class<T
 	/*
 	 * send command without response
 	 */
-	@SuppressWarnings("unused")
 	private void voidCommand(final String command) throws IOException {
 		synchronized (this.asyncMutex) {
 			this.out.write(command + "\n");
@@ -338,7 +337,9 @@ public void kickDevice(String path) throws IOException, JSONException {
 	 */
 	void handleDisconnected() throws IOException {
 		synchronized (this.asyncMutex) {
-			socket.close();
+			if (socket != null) {
+				socket.close();
+			}
 			this.socket = new Socket(server, port);
 			this.in = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));
 			this.out = new BufferedWriter(new OutputStreamWriter(this.socket.getOutputStream()));
diff --git a/src/main/java/de/taimos/gpsd4java/backend/SocketThread.java b/src/main/java/de/taimos/gpsd4java/backend/SocketThread.java
@@ -52,12 +52,7 @@ public class SocketThread extends Thread {
 	 */
 	public SocketThread(final BufferedReader reader, final GPSdEndpoint endpoint, 
 							  final AbstractResultParser resultParser, final boolean daemon) {
-		if (reader == null) {
-			throw new IllegalArgumentException("reader can not be null!");
-		}
-		if (endpoint == null) {
-			throw new IllegalArgumentException("endpoint can not be null!");
-		}
+
 		if (resultParser == null) {
 			throw new IllegalArgumentException("resultParser can not be null!");
 		}
@@ -81,22 +76,24 @@ public SocketThread(final BufferedReader reader, final GPSdEndpoint endpoint, fi
 	
 	@Override
 	public void run() {
-		while (this.running.get()) {
-			try {
-				// read line from socket
-				final String s = this.reader.readLine();
-				if (s == null) {
-					break;
-				}
-				if (!s.isEmpty()) {
-					// parse line and handle it accordingly
-					this.endpoint.handle(this.resultParser.parse(s));
+		if (this.reader != null) {
+			while (this.running.get()) {
+				try {
+					// read line from socket
+					final String s = this.reader.readLine();
+					if (s == null) {
+						break;
+					}
+					if (!s.isEmpty()) {
+						// parse line and handle it accordingly
+						this.endpoint.handle(this.resultParser.parse(s));
+					}
+				} catch (final SocketException e) {
+					break; // stop 
+				} catch (final Exception e) {
+					// TODO handle this better
+					SocketThread.LOG.warn("Problem encountered while reading/parsing/handling line", e);
 				}
-			} catch (final SocketException e) {
-				break; // stop 
-			} catch (final Exception e) {
-				// TODO handle this better
-				SocketThread.LOG.warn("Problem encountered while reading/parsing/handling line", e);
 			}
 		}
 		if (running.get() && !Thread.interrupted()) {
@@ -106,13 +103,17 @@ public void run() {
 	}
 	
 	protected void retry() {
-		SocketThread.LOG.debug("Disconnected from GPS socket, retrying connection");
+		if (reader != null) {
+			SocketThread.LOG.debug("Disconnected from GPS socket, retrying connection");
+		} else {
+			SocketThread.LOG.debug("Connecting to GPSD socket");
+		}
 		
 		while (this.running.get()) {
 			try {
 				running.waitFor(this.endpoint.getRetryInterval());
 				this.endpoint.handleDisconnected();
-				SocketThread.LOG.debug("Reconnected to GPS socket");
+				SocketThread.LOG.debug("Connected to GPS socket");
 				running.set(false);
 			} catch (InterruptedException ix) {
 				break;
