I'm writing an sample app to create a Server on Android and a client to connect to PC. I put the serversocket in a thread of a service. Everything goes perfectly, until a few minutes after the screen goes off. This may be Android kill my server, I tried to put a full wake lock to my code and it wont kill anymore, however, I DO want the screen go off as usual.
Here is my code:
public class MessageListener extends Service {
private ServerSocket serverSocket;
#Override
public void onCreate() {
Log.v("Test", "Create service");
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
PowerManager.WakeLock wl=null;
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "My Tag");
wl.acquire();
startServer();
if(wl!=null) wl.release();
return START_STICKY;
}
private Runnable thread = new Runnable() {
#Override
public synchronized void run() {
try {
serverSocket = new ServerSocket(Integer.parseInt(5000));
ObjectInputStream in = null;
while (true) {
Socket client = serverSocket.accept();
Log.v("TCP", "S: Receiving...");
try {
in = new ObjectInputStream(client.getInputStream());
DataInController data = new DataInController(
getApplicationContext());
data.processDataIn(in.readObject(), client);
} catch (ClassNotFoundException e) {
System.out.println("TCP S: Error in PC Server Listener");
e.printStackTrace();
} finally {
client.close();
}
}
} catch (IOException e) {
}
}
};
private Thread serverThread;
private synchronized void startServer() {
if (serverThread == null) {
serverThread = new Thread(thread);
serverThread.start();
}
}
private synchronized void stopServer() {
if(serverThread!=null){
Thread t=serverThread;
serverThread=null;
t.interrupt();
}
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onDestroy() {
super.onDestroy();
Log.v("TCP", "Killing Service!!!!!!!!!!!!!!!!!!!!!!!");
if (serverSocket != null) {
try {
serverSocket.close();
stopServer();
Log.v("TCP", "Closed server socket");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Two things that worked for us:
Wi-Fi lock
Set the Wi-Fi sleep policy to never. Some devices will power down the Wi-Fi radio without this setting, even when a program has a lock on the Wi-Fi radio.
I found the problem. That is the router lost the connection to Android. I've tried to ping it and it said "unreachable", after re connect to wifi, it works, but after a while, it comes again
Also try to keep WakeLock. Doing both works for me.
Related
I've create an application, VPN service, which will block internet packets. Everything is working fine but now I want to stop this VPN service on a button click event so that packets are not blocked anymore.
I've tried to use stopService(name); and stopSelf();
but nothing happened. What am I doing wrong?
public class VpnServiceCls extends VpnService {
private Thread b;
private ParcelFileDescriptor c;
private PendingIntent a;
Builder builder = new Builder();
private static final String TAG = "VpnService";
#Override
public void onDestroy() {
// TODO Auto-generated method stub
Log.d(TAG, "you are in jghbgjyhb");
if (b != null) {
Log.d(TAG, "you are in destroy2");
b.interrupt();
}
}
public void StopMyVPN()
{
Log.d(TAG, "you are in jghbgjyhb 898");
stopSelf();
if (b != null) {
Log.d(TAG, "you are in destroy");
b.interrupt();
}
b.stop();
super.onDestroy();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
b= new Thread(new Runnable() {
#Override
public void run() {
try{
//here is my logic which is working fine
}
}
catch(Exception e)
{
Log.d(TAG, "you are out "+e.toString());
}
}
});//start the service
b.start();
return START_STICKY;
}
}
on button click i am calling StopMyVPN() function but notting happen
you must close and set null interface of vpn .mInterface is vpn interface.
public void StopMyVPN() {
try {
if (mInterface != null) {
mInterface.close();
mInterface = null;
}
isRunning = false;
} catch (Exception e) {
}
stopSelf();
}
you could Bind Activity to your service for calling StopMyVPN.
I also struggled with this issue. At the end I found that my problem was caused by parcelFileDescriptor which I was not closing, and that kept my service from destroy.
private fun stop(){
try {
parcelFileDescriptor.close()
} catch (ex: IOException) {
Log.e(TAG,"parcelFileDescriptor.close()", ex)
}
stopForeground(true)
stopSelf()
}
In a typical android service you can call stopSelf(); but in this case as it is VpnService, same should work only when you closed the interfaces.
So in VpnService when you build a Tun by doing establish() and get the interface. Now if you want to shutdown your VPN tunnel, then you need to first close this interface and then you need to stop all the threads that you have started, and then you are free to call stopSelf() and it should work.
I am creating an application that will monitor movements in a particular Android device (client) and report such instances to another Android device (server). Also, under specific conditions, the client will take a picture and transmit the image to the server.
I am using WiFi direct to setup the connection between the two devices. After that I am using socket connections as explained in the WiFi Direct Demo. I am using port 8988 to send the motion sensor events and I am using port 8987 to send the images capture.
On the server side, I am using two different instances of the same Async Task with serversocket connecting to different ports to listen for the incoming messages. Everything works fine as long as only the motion sensor events are being sent across. The first image capture is also being sent/received correctly. However, after that the server doesn't receive any additional messages. I tried having two different Async Task classes to avoid having two instances of the same class but that didn't work as well. I also tried having one as an Async Task and another as an Intent Service but even that doesn't work.
This is IntentService I am using to send the messages across to the server.
public class MessageSender extends IntentService {
public static final String EXTRAS_TIMEOUT = "timeout";
public static final String EXTRAS_ADDRESS = "go_host";
public static final String EXTRAS_PORT = "go_port";
public static final String EXTRAS_DATA = "data";
private Handler handler;
public MessageSender(String name) {
super(name);
}
public MessageSender() {
super("MessageTransferService");
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
handler = new Handler();
return super.onStartCommand(intent, flags, startId);
}
#Override
protected void onHandleIntent(Intent intent) {
String host = intent.getExtras().getString(EXTRAS_ADDRESS);
Socket socket = new Socket();
int port = intent.getExtras().getInt(EXTRAS_PORT);
byte[] data = intent.getExtras().getByteArray(EXTRAS_DATA);
int timeout = intent.getExtras().getInt(EXTRAS_TIMEOUT);
try {
socket.bind(null);
socket.connect((new InetSocketAddress(host, port)), timeout);
OutputStream stream = socket.getOutputStream();
stream.write(data);
} catch (final IOException e) {
handler.post(new Runnable() {
#Override
public void run() {
Toast.makeText(getApplicationContext(), "Exception has occurred: " + e.getMessage(),
Toast.LENGTH_SHORT).show();
}
});
} finally {
if (socket != null) {
if (socket.isConnected()) {
try {
socket.close();
/*handler.post(new Runnable() {
#Override
public void run() {
Toast.makeText(getApplicationContext(), "Socket Connection closed now..",
Toast.LENGTH_SHORT).show();
}
});*/
} catch (IOException e) {
// Give up
e.printStackTrace();
}
}
}
}
}
}
This is Async Task on the server that starts listeners on two ports (8987 and 8988) to receiver the information of motion sensor events and images.
public class MessageReceiver extends AsyncTask<Void, Void, String> {
private Context context;
private int port;
private Bitmap mBitmap;
public MessageReceiver(Context context, int port) {
this.context = context;
this.port = port;
}
#Override
protected String doInBackground(Void... params) {
try {
ServerSocket serverSocket = new ServerSocket(port);
Socket client = serverSocket.accept();
InputStream inputstream = client.getInputStream();
String returnString = "";
if (port == MainActivity.PORT_SENSOR_COMM) {
// do something
} else if (port == MainActivity.PORT_IMAGE_COMM) {
//do something
}
serverSocket.close();
return returnString;
} catch (Exception e) {
return "Exception Occurred:" + e.getMessage();
}
}
#Override
protected void onPostExecute(String result) {
boolean startNewTask = true;
if (port == MainActivity.PORT_SENSOR_COMM) {
//do something
} else if (port == MainActivity.PORT_IMAGE_COMM) {
//do something
}
//doing this to start listening for new messages again
new MessageReceiver(context, port).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
}
#Override
protected void onPreExecute() {
}
}
I am now wondering whether Android WiFiDirect allows parallel communication between two devices on different ports. Searched the docs but could'nt find much help. What I am doing wrong? What is the correct method to accomplish what I am trying to do? Any help would be greatly appreciated. Thanks for looking.
I'm very new with programming for android. I have two classes : main and btmanager. When i try to test my app on phone, all I get is a information that procees was killed. What am I doing wrong ?
Code implementation :
Main class :
public class MainActivity extends Activity {
BluetoothAdapter bluetooth = BluetoothAdapter.getDefaultAdapter();
Btmanager manager;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (bluetooth == null)
{
Toast.makeText(this, "Bluetooth is not enabled on this device", Toast.LENGTH_LONG).show();
System.exit(0);
}
}
#Override
public void onStart()
{
super.onStart();
if (!bluetooth.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, 2);
}
manager.run();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
public void closeApp (View view)
{
System.exit(0);
}
}
Btmanager class :
public class Btmanager extends Thread {
private final BluetoothSocket mmSocket;
private final BluetoothDevice mmDevice;
public static final UUID myUUID = UUID.fromString("0x1101");
BluetoothAdapter bluetooth = BluetoothAdapter.getDefaultAdapter();
public Btmanager(BluetoothDevice device) {
// Use a temporary object that is later assigned to mmSocket,
// because mmSocket is final
BluetoothSocket tmp = null;
mmDevice = device;
// Get a BluetoothSocket to connect with the given BluetoothDevice
try {
// MY_UUID is the app's UUID string, also used by the server code
tmp = device.createRfcommSocketToServiceRecord(myUUID);
} catch (IOException e) { }
mmSocket = tmp;
}
public void run() {
// Cancel discovery because it will slow down the connection
bluetooth.cancelDiscovery();
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
mmSocket.connect();
} catch (IOException connectException) {
// Unable to connect; close the socket and get out
try {
mmSocket.close();
} catch (IOException closeException) { }
return;
}
}
/** Will cancel an in-progress connection, and close the socket */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) { }
}
2 problems I see in your code:
You don't instantiate the Btmanager object, it is still null when you call run. (Will cause a NullPointerException - your app will crash).
You call the run method instead of the start method of the Btmanager. If you want the code in the run method to run in a new thread, you have to call start. Calling run will cause it to run in the same thread. This blocks your UI thread which may cause your app to crash, if it blocks for too long.
For test purporses, I don't use BTmanager class - in onStart() method I add new thread with connection implentation, but still without any results - app crash.
public void onStart()
{
super.onStart();
if (!bluetooth.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, 2);
}
new Thread(new Runnable()
{
public void run()
{
try {
//Create a Socket connection: need the server's UUID number of registered
socket = device.createRfcommSocketToServiceRecord(myUUID);
socket.connect();
Log.d("EF-BTBee", "Connectted");
}
catch (IOException e)
{
Log.e("EF-BTBee", "Error : ", e);
}
}
}).start();
}
I am starting a service from activity.The problem here is the service gets started started but the activity is not getting displayed.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
startService(new Intent(this, ServerActivity1.class));
}
In the service I am opening a socket via a simple function like this by using a timer.The service gets started as I am able to see in logs but the view(R.layout.main) never gets displayed and after some time the force close pop is displayed.
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onCreate() {
Toast.makeText(this, "sasa", Toast.LENGTH_SHORT).show();
timer.scheduleAtFixedRate( new TimerTask() {
public void run() {
read();
}
}, 0,50000);
Log.i("NoServer","Started1");
read();
}
#Override
public void onDestroy() {
}
#Override
public void onStart(Intent intent, int startid) {
Log.i("Home","Listening on IP: " + SERVERIP+"\n");
}
public void read()
{
SERVERIP = getLocalIpAddress();
Log.i("Home","Listening on IP: " + SERVERIP+"\n");
if (SERVERIP != null) {
Log.i("Home","Listening on IP: " + SERVERIP+"\n");
}
try {
serverSocket = new ServerSocket(SERVERPORT);
} catch (IOException e1) {
e1.printStackTrace();
}
while (true) {
Socket client;
Log.i("Home","Listening on IP: " + SERVERIP+"\n");
try {
client = serverSocket.accept();
Log.i("Home","Listening on IP: " + SERVERIP+"\n");
BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
while ((line = in.readLine()) != null) {
serverSocket.close();
read();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
Its because your UI thread (main) is being shared by service unless you define your service in a separate process in manifest. If you start your service in activity's onResume method, till then your service would be visible but still may cause ANR depending on the time (max 5 secs) it takes to complete requests in service.
Its better to put all the socket stuff (or any expensive calls) of your service in a separate thread. In that case, your app will not hang or crash due to ANR.
You should use ThreadHandler and Handler to execute Messages and/or Runnables in a separate thread inside Service.
I have got a service which runs a thread. The thread save some data in a file (in the sdcard). When Android goes to sleep, I need that the service and the thread continue running. I tried it with a PARTIAL_WAKE_LOCK, but it doesn't work; the thread stops while Android is sleeping. Other locks like FULL_WAKE_LOCK works, but I need to use PARTIAL_WAKE_LOCK because, in the future, in that thread I will read from a serial port and I don't care the screen turn off.
I don't know if I have got some mistake in the code, or if I don't understand the PARTIAL_WAKE_LOCK. Somebody can tell me why my solution doesn't wrok?
This is part of the code of the main activity, where the service is stareted:
public void onClick(View v) {
if (SerialPortService.WAKELOCK == null) {
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
SerialPortService.WAKELOCK = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, SerialPortService.WL_TAG);
SerialPortService.WAKELOCK.acquire();
startService(new Intent(getApplicationContext(), SerialPortService.class));
}
}
This is the code of the service:
public class SerialPortService extends Service {
public static String WL_TAG = "serial_port_wl_tag";
public static PowerManager.WakeLock WAKELOCK = null;
private BufferedWriter out = null;
private ReadThread readThread;
public IBinder onBind(Intent intent) {
return null;
}
public void onCreate() {
super.onCreate();
try {
File root = Environment.getExternalStorageDirectory();
if (root.canWrite()){
File dataFile = new File(root, "batterytest.txt");
FileWriter dataFileWritter = new FileWriter(dataFile);
out = new BufferedWriter(dataFileWritter);
}
} catch (IOException ioe) {
Log.d("TEST", "Could not open file " + ioe.getMessage());
}
readThread = new ReadThread();
readThread.start();
}
public void onDestroy() {
if (readThread != null) readThread.interrupt();
WAKELOCK.release();
WAKELOCK = null;
try {
out.close();
} catch (IOException ioe) {
Log.d("TEST", "Could not close file " + ioe.getMessage());
}
super.onDestroy();
}
private class ReadThread extends Thread {
public void run() {
super.run();
while (!isInterrupted()) {
try {
Thread.sleep(5000);
if (out != null) {
Calendar now = Calendar.getInstance();
out.write(now.getTime().toString());
out.newLine();
} catch (IOException ioe) {
Log.d("TEST", "Could not read file " + ioe.getMessage());}
return;
} catch (InterruptedException e) {
return;
}
}
}
}
}
Well, I will answer my question. My code is ok. I've discovered few minutes ago that the problem is the implementation of the PowerManager in the Eken M009S tablets, (a chinese tablet), the device where I've made the tests. In other devices, like in Samsung's cell phones, the PARTIAL_WAKE_LOCK works perfectly.