Develop Reference

how to stop a service running multiple instance?

I am developing a android app, which will update device location after 4 seconds interval and depending on the response received from the server it will open specific activity.
Problem 1) In some case it will open up a activity like incoming phone call with sound. I am facing problem when I am removing the app from recent app. I noticed the poll function is running twice at the same time, and multiple media is playing at the same time.
Problem 2) I am using Service intead of IntentService(I am a beginner and not sure which will be better). The background service should run even the phone goes to sleep mode, just like WhatsApp or other messenger run.
As the file is big enough, I am attaching only important part
public class TaxiNorrService extends Service implements LocationListener {
...
...
final Handler poll_handler = new Handler();
private NotificationManager mNM;
private final Actions actions = new Actions();
public Ringtone r;
private String newtext;
private Runnable BreakRunnable;
private Runnable poll_runnable;
private Handler BreakHandler;
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
poll_runnable = new Runnable() {
#Override
public void run() {
if(!App.isAutoBreak()){
if(BreakHandler !=null){
BreakHandler.removeCallbacks(BreakRunnable);
}
if(r != null) {
if (r.isPlaying()) {
r.stop();
}
}
}
if (actions.checkPermission(getApplicationContext())) {
checkGPS();
if(isNetworkAvailable()){
if(App.isPollOn()){
poll(latitude, longitude);
}
}else{
if(BreakHandler !=null){
BreakHandler.removeCallbacks(BreakRunnable);
}
boolean foregroud = false;
try {
foregroud = new ForegroundCheckTask().execute(getApplication()).get();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
boolean background = isMyServiceRunning(TaxiNorrService.class);
if(foregroud == true && background == true && App.isAppForground()){
if(!App.isLoadingVisible()){
Intent intent = new Intent(TaxiNorrService.this, Loading_activity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
}
}
}
}
poll_handler.postDelayed(this, 4000);
}
};
return Service.START_STICKY;
}
private void poll(double lat, double lon){
//Connected to API endpoint
}
...
...
#Override
public void onDestroy() {
if(r != null) {
if (r.isPlaying()) {
r.stop();
}
}
poll_handler.removeCallbacks(poll_runnable);
super.onDestroy();
}
}

I found the answer for my questions. The code written in the onStartCommand should be within onCreate function. This is because onCreate will execute when service starts first time, and onStartCommand will execute every time when you start the app. Please follow this topic,
Android - running a method periodically using postDelayed() call

Is the Android service still alive even after the onDestroy() be called?

For studying the Android service, I wrote a test program that have three button "bind service", "unbind service" and "send echo" on the screen. When clicked, they use bindService(), unbindService() and a Messenger to communicate with the service.
Here is the service codes:
public class MessengerService extends Service {
private final Messenger mMessenger = new Messenger(new TempHandler());
private class TempHandler extends Handler {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_SAY_HELLO:
Toast.makeText(getApplicationContext(), "Hi, there.", Toast.LENGTH_SHORT).show();
break;
case MSG_SAY_GOODBYE:
Toast.makeText(getApplicationContext(), "See you next time.", Toast.LENGTH_SHORT).show();
break;
case MSG_ECHO:
Toast.makeText(getApplicationContext(), "Received " + msg.arg1 + " from client.", Toast.LENGTH_SHORT).show();
Messenger replyMessenger = msg.replyTo;
Message replyMsg = Message.obtain(null, MSG_ECHO, msg.arg1, 0);
try {
replyMessenger.send(replyMsg);
} catch (RemoteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
default:
super.handleMessage(msg);
}
}
}
#Override
public IBinder onBind(Intent intent) {
Toast.makeText(getApplicationContext(), "Service bound", Toast.LENGTH_SHORT).show();
return mMessenger.getBinder();
}
#Override
public void onDestroy() {
Log.d("", "Service.onDestroy()...");
super.onDestroy();
}
}
And here is the activity code:
public class MessengerActivity extends Activity {
private Messenger mMessengerService;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity2);
Button bind = (Button) findViewById(R.id.button5);
bind.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
doBindService();
}
});
Button unbind = (Button) findViewById(R.id.button6);
unbind.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
doUnbindService();
}
});
Button echo = (Button) findViewById(R.id.button7);
echo.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
doSendEcho();
}
});
}
private void doBindService() {
Intent intent = new Intent(getApplicationContext(), MessengerService.class);
bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
}
private void doUnbindService() {
Message msg = Message.obtain(null, MessengerService.MSG_SAY_GOODBYE);
try {
mMessengerService.send(msg);
} catch (RemoteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
unbindService(mConnection);
}
private void doSendEcho() {
if (mMessengerService != null) {
Message msg = Message.obtain(null, MessengerService.MSG_ECHO, 12345, 0);
msg.replyTo = mMessenger;
try {
mMessengerService.send(msg);
} catch (RemoteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
private final Messenger mMessenger = new Messenger(new TempHandler());
private ServiceConnection mConnection = new ServiceConnection() {
#Override
public void onServiceConnected(ComponentName name, IBinder service) {
Toast.makeText(getApplicationContext(), "Service is connected.", Toast.LENGTH_SHORT).show();
mMessengerService = new Messenger(service);
Message msg = Message.obtain(null, MessengerService.MSG_SAY_HELLO);
try {
mMessengerService.send(msg);
} catch (RemoteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
public void onServiceDisconnected(ComponentName name) {
mMessengerService = null;
Toast.makeText(getApplicationContext(), "Service is disconnected.", Toast.LENGTH_SHORT).show();
}
};
private class TempHandler extends Handler {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MessengerService.MSG_ECHO:
Toast.makeText(getApplicationContext(), "Get the echo message (" + msg.arg1 + ")", Toast.LENGTH_SHORT).show();
break;
default:
super.handleMessage(msg);
}
}
}
}
When I click "bind service" and "send echo" button. I can see the service is connected and the message communication is good. And then click "unbind service", I saw the service onDestroy() be called, so I expect the service is stopped and should not respond to the coming message again. But actually is, the service seems still alive and I could get the echo message again when click the "send echo" button. So I'm wondering is there anything I made incorrect? Or maybe I'm not fully understand about the service?
Hope someone can help, thanks.

A service is "bound" when an application component binds to it by calling bindService(). A bound service offers a client-server interface that allows components to interact with the service, send requests, get results, and even do so across processes with interprocess communication (IPC). A bound service runs only as long as another application component is bound to it.
http://developer.android.com/guide/components/services.html
A service will shut down after all bindService() calls have had their corresponding unbindService() calls. If there are no bound clients, then the service will also need stopService() if and only if somebody called startService() on the service.
Drawing from the below link.
How to check if a service is running on Android?.
private void doSendEcho() {
if(isMyServiceRunning()) // if service is running
{
if (mMessengerService != null) {
Message msg = Message.obtain(null, MessengerService.MSG_ECHO, 12345, 0);
msg.replyTo = mMessenger;
try {
mMessengerService.send(msg);
} catch (RemoteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
private boolean isMyServiceRunning() {
ActivityManager manager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
if (MessengerService.class.getName().equals(service.service.getClassName())) {
return true;
}
}
return false;
}
#Override
protected void onStop() {
super.onStop();
// Unbind from the service
unbindService(mConnection);
Log.i("Stopped!",""+isMyServiceRunning());
Log.i("stopped", "Service Stopped");
}
Example:
I tested the below it works fine.
public class MessengerService extends Service {
public static final int MSG_SAY_HELLO =1;
public static final int MSG_SAY_GOODBYE =2;
ArrayList<Messenger> mClients = new ArrayList<Messenger>();
private final Messenger mMessenger = new Messenger(new TempHandler());
private class TempHandler extends Handler {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_SAY_HELLO:
mClients.add(msg.replyTo);
Toast.makeText(getApplicationContext(), "Hi, there.", Toast.LENGTH_SHORT).show();
break;
case MSG_SAY_GOODBYE:
mClients.add(msg.replyTo);
break;
default:
super.handleMessage(msg);
}
}
}
#Override
public IBinder onBind(Intent intent) {
Toast.makeText(getApplicationContext(), "Service bound", Toast.LENGTH_SHORT).show();
return mMessenger.getBinder();
}
#Override
public void onDestroy() {
Log.i("MessengerService", "Service Destroyed...");
super.onDestroy();
}
}
MainAactivity.java
public class MainActivity extends Activity {
boolean mIsBound=false;
Messenger mService = null;
private boolean isMyServiceRunning() {
ActivityManager manager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
if (MessengerService.class.getName().equals(service.service.getClassName())) {
return true;
}
}
return false;
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button bind = (Button) findViewById(R.id.button1);
bind.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
doBindService();
}
});
Button unbind = (Button) findViewById(R.id.button2);
unbind.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
doUnbindService();
}
});
}
class TempHandler extends Handler {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MessengerService.MSG_SAY_GOODBYE:
Toast.makeText(MainActivity.this,"Received from service: " + msg.arg1,1000).show();
break;
default:
super.handleMessage(msg);
}
}
}
/**
* Target we publish for clients to send messages to IncomingHandler.
*/
final Messenger mMessenger = new Messenger(new TempHandler());
/**
* Class for interacting with the main interface of the service.
*/
private ServiceConnection mConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className,
IBinder service) {
// This is called when the connection with the service has been
// established, giving us the service object we can use to
// interact with the service. We are communicating with our
// service through an IDL interface, so get a client-side
// representation of that from the raw service object.
mService = new Messenger(service);
// mCallbackText.setText("Attached.");
// We want to monitor the service for as long as we are
// connected to it.
try {
Message msg = Message.obtain(null,
MessengerService.MSG_SAY_HELLO);
msg.replyTo = mMessenger;
mService.send(msg);
// Give it some value as an example.
// msg = Message.obtain(null,
// MessengerService.MSG_E, this.hashCode(), 0);
// mService.send(msg);
} catch (RemoteException e) {
// In this case the service has crashed before we could even
// do anything with it; we can count on soon being
// disconnected (and then reconnected if it can be restarted)
// so there is no need to do anything here.
}
// As part of the sample, tell the user what happened.
Toast.makeText(MainActivity.this, "remote_service_connected",
Toast.LENGTH_SHORT).show();
}
public void onServiceDisconnected(ComponentName className) {
// This is called when the connection with the service has been
// unexpectedly disconnected -- that is, its process crashed.
mService = null;
// mCallbackText.setText("Disconnected.");
// As part of the sample, tell the" user what happened.
Toast.makeText(MainActivity.this, "remote_service_disconnected",
Toast.LENGTH_SHORT).show();
}
};
void doBindService() {
// Establish a connection with the service. We use an explicit
// class name because there is no reason to be able to let other
// applications replace our component.
bindService(new Intent(MainActivity.this,
MessengerService.class), mConnection, Context.BIND_AUTO_CREATE);
mIsBound=true;
Toast.makeText(MainActivity.this, "Binding",1000).show();
}
void doUnbindService() {
if (mIsBound) {
// If we have received the service, and hence registered with
// it, then now is the time to unregister.
if (mService != null) {
try {
Message msg = Message.obtain(null,
MessengerService.MSG_SAY_GOODBYE);
msg.replyTo = mMessenger;
mService.send(msg);
} catch (RemoteException e) {
// There is nothing special we need to do if the service
// has crashed.
}
}
// Detach our existing connection.
unbindService(mConnection);
mIsBound = false;
Toast.makeText(MainActivity.this, "UnBinding"+isMyServiceRunning(),1000).show();
}
}
}

I personally find the terminology/nomenclature to be dissatisfying/misleading.
"onDestroy" and "stopService" might be better understood if they were called "FlagForAndroidOSDestruction" and "FlagForAndroidStopService".
If one downloads/compiles/runs any of the following examples, one can see that even when the OnHandleIntent is finished or stopService has been called, the process and even the service can still hang around! To see this simply launch the example(s) below, and then on your phone/tablet goto
Settings->Apps->Running->Show Running Services
and
Settings->Apps->Running->Show Cached Processes
When you see these, try launching a ton of other apps on the phone and THEN you'll see Android destroying said service & process.
http://developer.android.com/guide/components/services.html#ExtendingIntentService
http://android-er.blogspot.com/2013/03/stop-intentservice.html
How to check all the running services in android?

Yes, this is a conclusion drawn out of the official docs:
A service can be both started and have connections bound to it. In such a case, the system will keep the service running as long as either it is started or there are one or more connections to it with the Context.BIND_AUTO_CREATE flag. Once neither of these situations hold, the service's onDestroy() method is called and the service is effectively terminated. All cleanup (stopping threads, unregistering receivers) should be complete upon returning from onDestroy().

From http://developer.android.com/guide/components/services.html :
These two paths are not entirely separate. That is, you can bind to a service that was already started with startService(). For example, a background music service could be started by calling startService() with an Intent that identifies the music to play. Later, possibly when the user wants to exercise some control over the player or get information about the current song, an activity can bind to the service by calling bindService(). In cases like this, stopService() or stopSelf() does not actually stop the service until all clients unbind.
So you have to call unBindService() and after stopService()

This link (Do I need to call both unbindService and stopService for Android services?) says that you need to call stopService before unbindService.
Try that.

onServiceConnected sometimes not called after bindService on some devices

I've looked at a number of other threads with similar titles, and none seem to cover my problem. So, here goes.
I'm using the Google market expansion files (apkx) library and sample code, with a few modifications. This code relies on receiving callbacks from a service which handles background downloading, licence checks etc.
I have a bug where the service doesn't get correctly attached, which results in a softlock. To make this more unhelpful, this bug never happens on some devices, but occurs about two thirds of the time on other devices. I believe it to be independent of Android version, certainly I have two devices running 2.3.4, one of which (a Nexus S) doesn't have the problem, the other (an HTC Evo 3D) does.
To attempt to connect to the service, bindService is called and returns true. OnBind then gets called as expected and returns a sensible value but (when the bug occurs) onServiceConnected doesn't happen (I've waited 20 minutes just in case).
Has anyone else seen anything like this? If not, any guesses for what I might have done to cause such behaviour? If no-one has any thoughts, I'll post some code tomorrow.
EDIT: Here's the relevant code. If I've missed anything, please ask.
Whilst adding this code, I found a minor bug. Fixing it caused the frequency of the problem I'm trying to solve to change from 2 times in 3 to about 1 time in 6 on the phone I'm testing it on; no idea about effects on other phones. This continues to suggest to me a race condition or similar, but I've no idea what with.
OurDownloaderActivity.java (copied and changed from Google sample code)
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
...
//Test the licence is up to date
//if (current stored licence has expired)
{
startLicenceCheck();
initializeDownloadUI();
return;
}
...
}
#Override
protected void onResume() {
if (null != mDownloaderClientStub) {
mDownloaderClientStub.connect(this);
}
super.onResume();
}
private void startLicenceCheck()
{
Intent launchIntent = OurDownloaderActivity.this
.getIntent();
Intent intentToLaunchThisActivityFromNotification = new Intent(OurDownloaderActivity
.this, OurDownloaderActivity.this.getClass());
intentToLaunchThisActivityFromNotification.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |
Intent.FLAG_ACTIVITY_CLEAR_TOP);
intentToLaunchThisActivityFromNotification.setAction(launchIntent.getAction());
if (launchIntent.getCategories() != null) {
for (String category : launchIntent.getCategories()) {
intentToLaunchThisActivityFromNotification.addCategory(category);
}
}
// Build PendingIntent used to open this activity from Notification
PendingIntent pendingIntent = PendingIntent.getActivity(OurDownloaderActivity.this,
0, intentToLaunchThisActivityFromNotification,
PendingIntent.FLAG_UPDATE_CURRENT);
DownloaderService.startLicenceCheck(this, pendingIntent, OurDownloaderService.class);
}
initializeDownloadUI()
{
mDownloaderClientStub = DownloaderClientMarshaller.CreateStub
(this, OurDownloaderService.class);
//do a load of UI setup
...
}
//This should be called by the Stub's onServiceConnected method
/**
* Critical implementation detail. In onServiceConnected we create the
* remote service and marshaler. This is how we pass the client information
* back to the service so the client can be properly notified of changes. We
* must do this every time we reconnect to the service.
*/
#Override
public void onServiceConnected(Messenger m) {
mRemoteService = DownloaderServiceMarshaller.CreateProxy(m);
mRemoteService.onClientUpdated(mDownloaderClientStub.getMessenger());
}
DownloaderService.java (in Google market expansion library but somewhat edited )
//this is the onBind call that happens fine; the value it returns is definitely not null
#Override
public IBinder onBind(Intent paramIntent) {
return this.mServiceMessenger.getBinder();
}
final private IStub mServiceStub = DownloaderServiceMarshaller.CreateStub(this);
final private Messenger mServiceMessenger = mServiceStub.getMessenger();
//MY CODE, derived from Google's code
//I have seen the bug occur with a service started by Google's code too,
//but this code happens more often so is more repeatably related to the problem
public static void startLicenceCheck(Context context, PendingIntent pendingIntent, Class<?> serviceClass)
{
String packageName = serviceClass.getPackage().getName();
String className = serviceClass.getName();
Intent fileIntent = new Intent();
fileIntent.setClassName(packageName, className);
fileIntent.putExtra(EXTRA_LICENCE_EXPIRED, true);
fileIntent.putExtra(EXTRA_PENDING_INTENT, pendingIntent);
context.startService(fileIntent);
}
#Override
protected void onHandleIntent(Intent intent) {
setServiceRunning(true);
try {
final PendingIntent pendingIntent = (PendingIntent) intent
.getParcelableExtra(EXTRA_PENDING_INTENT);
if (null != pendingIntent)
{
mNotification.setClientIntent(pendingIntent);
mPendingIntent = pendingIntent;
} else if (null != mPendingIntent) {
mNotification.setClientIntent(mPendingIntent);
} else {
Log.e(LOG_TAG, "Downloader started in bad state without notification intent.");
return;
}
if(intent.getBooleanExtra(EXTRA_LICENCE_EXPIRED, false))
{
//we are here due to startLicenceCheck
updateExpiredLVL(this);
return;
}
...
}
}
//MY CODE, based on Google's, again
public void updateExpiredLVL(final Context context) {
Context c = context.getApplicationContext();
Handler h = new Handler(c.getMainLooper());
h.post(new LVLExpiredUpdateRunnable(c));
}
private class LVLExpiredUpdateRunnable implements Runnable
{
LVLExpiredUpdateRunnable(Context context) {
mContext = context;
}
final Context mContext;
#Override
public void run() {
setServiceRunning(true);
mNotification.onDownloadStateChanged(IDownloaderClient.STATE_LVL_UPDATING);
String deviceId = getDeviceId(mContext);
final APKExpansionPolicy aep = new APKExpansionPolicy(mContext,
new AESObfuscator(getSALT(), mContext.getPackageName(), deviceId));
// Construct the LicenseChecker with a Policy.
final LicenseChecker checker = new LicenseChecker(mContext, aep,
getPublicKey() // Your public licensing key.
);
checker.checkAccess(new LicenseCheckerCallback() {
...
});
}
}
DownloaderClientMarshaller.java (in Google market expansion library)
public static IStub CreateStub(IDownloaderClient itf, Class<?> downloaderService) {
return new Stub(itf, downloaderService);
}
and the Stub class from the same file:
private static class Stub implements IStub {
private IDownloaderClient mItf = null;
private Class<?> mDownloaderServiceClass;
private boolean mBound;
private Messenger mServiceMessenger;
private Context mContext;
/**
* Target we publish for clients to send messages to IncomingHandler.
*/
final Messenger mMessenger = new Messenger(new Handler() {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_ONDOWNLOADPROGRESS:
Bundle bun = msg.getData();
if ( null != mContext ) {
bun.setClassLoader(mContext.getClassLoader());
DownloadProgressInfo dpi = (DownloadProgressInfo) msg.getData()
.getParcelable(PARAM_PROGRESS);
mItf.onDownloadProgress(dpi);
}
break;
case MSG_ONDOWNLOADSTATE_CHANGED:
mItf.onDownloadStateChanged(msg.getData().getInt(PARAM_NEW_STATE));
break;
case MSG_ONSERVICECONNECTED:
mItf.onServiceConnected(
(Messenger) msg.getData().getParcelable(PARAM_MESSENGER));
break;
}
}
});
public Stub(IDownloaderClient itf, Class<?> downloaderService) {
mItf = itf;
mDownloaderServiceClass = downloaderService;
}
/**
* Class for interacting with the main interface of the service.
*/
private ServiceConnection mConnection = new ServiceConnection() {
//this is the critical call that never happens
public void onServiceConnected(ComponentName className, IBinder service) {
// This is called when the connection with the service has been
// established, giving us the object we can use to
// interact with the service. We are communicating with the
// service using a Messenger, so here we get a client-side
// representation of that from the raw IBinder object.
mServiceMessenger = new Messenger(service);
mItf.onServiceConnected(
mServiceMessenger);
mBound = true;
}
public void onServiceDisconnected(ComponentName className) {
// This is called when the connection with the service has been
// unexpectedly disconnected -- that is, its process crashed.
mServiceMessenger = null;
mBound = false;
}
};
#Override
public void connect(Context c) {
mContext = c;
Intent bindIntent = new Intent(c, mDownloaderServiceClass);
bindIntent.putExtra(PARAM_MESSENGER, mMessenger);
if ( !c.bindService(bindIntent, mConnection, 0) ) {
if ( Constants.LOGVV ) {
Log.d(Constants.TAG, "Service Unbound");
}
}
}
#Override
public void disconnect(Context c) {
if (mBound) {
c.unbindService(mConnection);
mBound = false;
}
mContext = null;
}
#Override
public Messenger getMessenger() {
return mMessenger;
}
}
DownloaderServiceMarshaller.java (in Google market expansion library, unchanged)
private static class Proxy implements IDownloaderService {
private Messenger mMsg;
private void send(int method, Bundle params) {
Message m = Message.obtain(null, method);
m.setData(params);
try {
mMsg.send(m);
} catch (RemoteException e) {
e.printStackTrace();
}
}
public Proxy(Messenger msg) {
mMsg = msg;
}
#Override
public void requestAbortDownload() {
send(MSG_REQUEST_ABORT_DOWNLOAD, new Bundle());
}
#Override
public void requestPauseDownload() {
send(MSG_REQUEST_PAUSE_DOWNLOAD, new Bundle());
}
#Override
public void setDownloadFlags(int flags) {
Bundle params = new Bundle();
params.putInt(PARAMS_FLAGS, flags);
send(MSG_SET_DOWNLOAD_FLAGS, params);
}
#Override
public void requestContinueDownload() {
send(MSG_REQUEST_CONTINUE_DOWNLOAD, new Bundle());
}
#Override
public void requestDownloadStatus() {
send(MSG_REQUEST_DOWNLOAD_STATE, new Bundle());
}
#Override
public void onClientUpdated(Messenger clientMessenger) {
Bundle bundle = new Bundle(1);
bundle.putParcelable(PARAM_MESSENGER, clientMessenger);
send(MSG_REQUEST_CLIENT_UPDATE, bundle);
}
}
private static class Stub implements IStub {
private IDownloaderService mItf = null;
final Messenger mMessenger = new Messenger(new Handler() {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_REQUEST_ABORT_DOWNLOAD:
mItf.requestAbortDownload();
break;
case MSG_REQUEST_CONTINUE_DOWNLOAD:
mItf.requestContinueDownload();
break;
case MSG_REQUEST_PAUSE_DOWNLOAD:
mItf.requestPauseDownload();
break;
case MSG_SET_DOWNLOAD_FLAGS:
mItf.setDownloadFlags(msg.getData().getInt(PARAMS_FLAGS));
break;
case MSG_REQUEST_DOWNLOAD_STATE:
mItf.requestDownloadStatus();
break;
case MSG_REQUEST_CLIENT_UPDATE:
mItf.onClientUpdated((Messenger) msg.getData().getParcelable(
PARAM_MESSENGER));
break;
}
}
});
public Stub(IDownloaderService itf) {
mItf = itf;
}
#Override
public Messenger getMessenger() {
return mMessenger;
}
#Override
public void connect(Context c) {
}
#Override
public void disconnect(Context c) {
}
}
/**
* Returns a proxy that will marshall calls to IDownloaderService methods
*
* #param ctx
* #return
*/
public static IDownloaderService CreateProxy(Messenger msg) {
return new Proxy(msg);
}
/**
* Returns a stub object that, when connected, will listen for marshalled
* IDownloaderService methods and translate them into calls to the supplied
* interface.
*
* #param itf An implementation of IDownloaderService that will be called
* when remote method calls are unmarshalled.
* #return
*/
public static IStub CreateStub(IDownloaderService itf) {
return new Stub(itf);
}

What is the proper way to update activity based on Network responses?

I am implementing an application which is kind of VOIP application. So my application is kind of network application. Now I want to implement two part in my application, one is GUI part and one is network part. My GUI part will just contain activities and handling of user interaction. My Network part should handle all network related activities like handling incoming network data and sending data to network based on GUI interaction. Now whenever there is any incoming data, I want to update some activity whose reference is not there in Network module. So what could be the best way to update activity from some other class? In my case some other class is my Network class. So in short I would like to ask that what should be the architecture in such scenario? i.e. Network part should run in separate thread and from there it should update GUI?

Depending on the type/size of data you need to send to the activity, you can use one of a number of options.
Use one of the methods described here.
Use a BroadcastReceiver: register it in the Activity and then fire off matching Intents in the Service that handles the networking code.
Make your Activity bind to your Service and then pass in a Handler that you send Messages to.

I have written apps like this, and I prefer the Handler method. In fact I have written an Abstract Activity class to do all the hard work and simply extend it in any activity that want to be notified of a change.
To Use the following code, just get your Activity to extend UpdatableActivity and override the dataUpdated() method. This method is called when your Service notifies the handler that data has been updated. In the Service code put your code to do an update in the update() method (Or modify to call your existing code). This allows an activity to call this.updateService() to force an update. The service can call the sendMessageToUI() method to notify all interested activities that the data has been updated.
Here is what the abstract activity looks like:
public abstract class UpdatableActivity extends Activity {
public static final String TAG = "UpdatableActivity (Abstract)";
private final Messenger mMessenger = new Messenger(new IncomingHandler());
private Messenger mService = null;
private boolean mIsBound;
protected class IncomingHandler extends Handler {
#Override
public void handleMessage(Message msg) {
if (Constants.LOG_DEBUG) Log.d(TAG, "Service has notified us of an update: ");
switch (msg.arg1) {
case UpdateService.MSG_DATA_UPDATED:
dataUpdated();
break;
default: super.handleMessage(msg);
}
}
}
private ServiceConnection mConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className, IBinder service) {
mService = new Messenger(service);
try {
Message msg = Message.obtain(null, UpdateService.MSG_REGISTER_CLIENT);
msg.replyTo = mMessenger;
mService.send(msg);
} catch (RemoteException e) {
// In this case the service has crashed before we could even do anything with it
}
}
public void onServiceDisconnected(ComponentName className) {
// This is called when the connection with the service has been unexpectedly disconnected - process crashed.
mService = null;
}
};
/**Override this method in you acctivity to handle the update */
public abstract void dataUpdated();
void doBindService() {
if (Constants.LOG_DEBUG) Log.d(TAG, "Binding to service...");
bindService(new Intent(this, UpdateService.class), mConnection, Context.BIND_AUTO_CREATE);
mIsBound = true;
}
void doUnbindService() {
if (mIsBound) {
// If we have received the service, and hence registered with it, then now is the time to unregister.
if (mService != null) {
try {
Message msg = Message.obtain(null, UpdateService.MSG_UNREGISTER_CLIENT);
msg.replyTo = mMessenger;
mService.send(msg);
} catch (RemoteException e) {
// There is nothing special we need to do if the service has crashed.
}
}
// Detach our existing connection.
unbindService(mConnection);
mIsBound = false;
}
}
public void updateService() {
if (Constants.LOG_DEBUG) Log.d(TAG,"Updating Service...");
if (mIsBound) {
if (mService != null) {
try {
Message msg = Message.obtain(null, UpdateService.MSG_SET_INT_VALUE, UpdateService.MSG_DO_UPDATE, 0);
msg.replyTo = mMessenger;
mService.send(msg);
} catch (RemoteException e) {
if (Constants.LOG_ERROR) Log.e(TAG,Log.getStackTraceString(e));
}
}
} else {
if (Constants.LOG_DEBUG) Log.d(TAG, "Fail - service not bound!");
}
}
pu
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.doBindService();
}
#Override
protected void onDestroy() {
super.onDestroy();
try {
doUnbindService();
} catch (Throwable t) {
if (Constants.LOG_ERROR) Log.e(TAG, "Failed to unbind from the service", t);
}
}
}
And here is what the Service looks Like:
public class UpdateService extends Service {
public static final String TAG = "UpdateService";
public static final int MSG_DATA_UPDATED = 0;
public static final int MSG_REGISTER_CLIENT = 1;
public static final int MSG_UNREGISTER_CLIENT = 2;
public static final int MSG_DO_UPDATE = 3;
public static final int MSG_SET_INT_VALUE = 4;
private static boolean isRunning = false;
private Handler handler = new IncomingHandler();
private final Messenger mMessenger = new Messenger(handler);
private ArrayList<Messenger> mClients = new ArrayList<Messenger>(); // Keeps track of all current registered clients.
#Override
public IBinder onBind(Intent intent) {
return mMessenger.getBinder();
}
class IncomingHandler extends Handler { // Handler of incoming messages from clients.
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_REGISTER_CLIENT:
mClients.add(msg.replyTo);
break;
case MSG_UNREGISTER_CLIENT:
mClients.remove(msg.replyTo);
break;
case MSG_SET_INT_VALUE:
switch (msg.arg1) {
case MSG_DO_UPDATE:
if (Constants.LOG_DEBUG) Log.d(TAG,"UI has asked to update");
update();
break;
}
break;
default:
super.handleMessage(msg);
}
}
}
private void sendMessageToUI() {
if (Constants.LOG_DEBUG) Log.d(TAG, "Notifying "+mClients.size()+" UI clients that an update was completed");
for (int i=mClients.size()-1; i>=0; i--) {
try {
// Send data as an Integer
mClients.get(i).send(Message.obtain(null, MSG_SET_INT_VALUE, MSG_DATA_UPDATED, 0));
} catch (RemoteException e) {
// The client is dead. Remove it from the list; we are going through the list from back to front so this is safe to do inside the loop.
mClients.remove(i);
}
}
}
public static boolean isRunning()
{
return isRunning;
}
#Override
public void onCreate() {
super.onCreate();
isRunning = true;
if (Constants.LOG_DEBUG) Log.d(TAG, "Service Started");
update();
}
#Override
public void onDestroy() {
if (Constants.LOG_DEBUG) Log.d(TAG, "Service Destroyed");
isRunning = false;
}
private void update() {
/**Your code to do an update goes here */
}
}

Yes, personally i think that the network and UI should be in separate threads. The way I tend to communicate between the two, which is probably not the recommended proper way, but it works for me, is to create a global variable in your application class. hope this helps a little

I would directly post to the main UI thread,
Handler mHandler = new Handler(Looper.getMainLooper());
mHandler.post(new Runnable() {...});

Android Local Service Architecture

I'm trying to implement a service to handle the communication with the server for the following code. I don't know much about the design architecture for these.
Here is my service class
public class BgService extends Service {
private static final String TAG = BgService.class.getSimpleName();
private Timer timer;
SendJsonRequest sjr;
private TimerTask updateTask = new TimerTask(){
#Override
public void run(){
try{
SendJsonRequest sjr = new SendJsonRequest();
sjr.carMake();
Log.i(TAG, "LOOK AT ME");
}
catch(Exception e){
Log.w(TAG,e);
}
}
};
#Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
#Override
public void onCreate(){
super.onCreate();
Log.i(TAG, "Service creating");
timer = new Timer("Server listening timer");
timer.schedule(updateTask, 1000L, 60*1000L);
}
#Override
public void onDestroy(){
super.onDestroy();
Log.i(TAG, "Service Destroying");
timer.cancel();
timer = null;
}
}
Here is my SendJsonRequest class
public class SendJsonRequest{
private static final String TAG = "SendJsonRequest";
private static String URL = "xxxxxxxxx";
private static String infoRec;
public static void createJsonObj(String path, Map x){
infoRec = CreateJsonRequest.jsonRequest(URL+path, x );
System.out.println(infoRec);
}
public static void carMake(){
String path = "/CarMake";
Map<String, Object> z = new HashMap<String,Object>();
z.put("Name", "Ford");
z.put("Model", "Mustang");
createJsonObj(path, z);
}
}
Here is my CreateJsonObject class
public class CreateJsonRequest {
public static String jsonRequest(String URL, Map<String,Object> params){
try{
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(URL);
JSONObject holder = new JSONObject();
for (Map.Entry<String, Object> m : params.entrySet()){
try {
holder.put(m.getKey(), m.getValue());
}
catch (JSONException e) {
Log.e("Hmmmm", "JSONException : "+e);
}
}
StringEntity se;
se = new StringEntity(holder.toString());
httpPost.setEntity(se);
httpPost.setHeader("Accept", "text/json");
httpPost.setHeader("Content-type", "text/json");
HttpResponse response = (HttpResponse) httpClient.execute(httpPost);
HttpEntity entity = response.getEntity();
if(entity != null){
InputStream is = entity.getContent();
Header contentEncoding = response.getFirstHeader("Content-Encoding");
String result= convertToString(is);
is.close();
System.out.println(result);
return result;
}
}
catch(Exception e)
{
e.printStackTrace();
}
return null;
}
Sorry for the massive amount of code. How I implemented my service is obviously not correct, I just have no clue where to start to get a service handling the json requests to the server. Thanks in advance.
To be more clear, this did work on a button click, now I'm trying to get it to all run in the background with the service. So I guess my question is what goes where in the service?
My activity successfully starts the service, the service would work and print "look at me" to the logcat every minute. Then I added the try{ sjr.carMake()} and it catches an exception.

You can use a broadcast receiver. This is a way to have your code start at certain times indicated by Android OS - for example, you can have it start when Android finished booting up (this is where I run my services usually.
The best way is to use the AlarmManager class, and tell your service how often to run.
Tell us more about what you're trying to do, and what the problem is, and we can give you a more concise answer...
UPDATE:
Have you created an entry in the manifest.xml file for the service?
UPDATE
Here is how I'm doing it in my application. This is your "hook" to the OS. It's going to fire when it finishes booting (don't forget to make in entry in the manifest for this!)
public class TmBroadcastReceiver extends BroadcastReceiver {
#Override
public void onReceive(final Context context, final Intent bootintent) {
try{
Log.i("Taskmotion-ROBOT", "Robot Broadcast signal received on Boot. Trying to start Alarm scheduler");
Intent mServiceIntent = new Intent(context, ServiceAlarm.class);
context.startService(mServiceIntent);
}
catch(Exception e)
{
Log.i("Taskmotion", "Failed to start service...");
}
}
}
This Broadcast receiver calls a service that implements the AlarmManager class. The alarm manager sets up a schedule to run my service at a specified interval. Note that the alarms are deleted when the phone is shut down - but then recreated again when process is repeated as the phone boots back up and runs the BroadcastReceiver again.
public class ServiceAlarm extends Service {
private PendingIntent mAlarmSender;
#Override
public void onCreate() {
try{
Log.i("Taskmotion-ROBOT", "Setting Service Alarm Step 1");
mAlarmSender = PendingIntent.getService(this.getApplicationContext(),
0, new Intent(this.getApplicationContext(), BackgroundService.class), 0);
}
catch(Exception e)
{
Log.i("Taskmotion-ROBOT", "Problem at 1 :" + e.toString());
}
long firstTime = SystemClock.elapsedRealtime();
Log.i("Taskmotion-ROBOT", "Setting Service Alarm Step 2");
// Schedule the alarm!
AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
am.setRepeating(AlarmManager.ELAPSED_REALTIME,
firstTime, AlarmManager.INTERVAL_HOUR, mAlarmSender);
this.stopSelf();
}
#Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
}
I haven't refactored this code yet, it was my first go at it. I see now that I'm looking at it again that I could probably do the scheduling inside the BroadcastReceiver, but for the sake of getting you something that works, I'll continue.
As indicated by AlarmManager.INTERVAL_HOUR, my service will run once an hour. The service that I want to run is defined in the pendingIntent (BackgroundService.class). This is where you put your own service class.
I reworked your service class for you, and removed the timer (functionality replaced by the BroadcastReceiver & AlarmManager).
public class BgService extends Service {
private static final String TAG = BgService.class.getSimpleName();
SendJsonRequest sjr;
#Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
#Override
public void onCreate(){
super.onCreate();
Log.i(TAG, "Service creating");
//DO YOUR WORK WITH YOUR JSON CLASS HERE
//**************************************
//Make sure to call stopSelf() or your service will run in the background, chewing up
//battery life like rocky mountain oysters!
this.stopSelf();
}
#Override
public void onDestroy(){
super.onDestroy();
}
}