I am updaiting database on each app launch, i was using IntentService before, but my activity was starting before data is updated, so data list was empty, i have rewriten it using Service(i have created my own Service acting like IntentService so i could controll thread created by the Service). As you see first of all i am saving data, and only after that i am starting my activity. But my activity is starting before data is saved anyway, any suggestions why, or how can i fix this?
Also
If you have some expirience working with ORM/Database async it would be great, i am just trying to learn how to work with database properly. Any suggestions are apreciated.
public class DatabaseWorkService extends Service {
private ServiceHandler mServiceHandler;
private DatabaseReference mDatabase;
private ConnectivityManager conMan;
private NetworkInfo netInfo;
private String currentTask;
private Intent tempIntent;
private Looper mServiceLooper;
private ResultReceiver resultReceiver;
private Context context =this;
public DatabaseWorkService delegate = null;
// Handler that receives messages from the thread
private final class ServiceHandler extends Handler {
public ServiceHandler(Looper looper) {
super(looper);
}
#Override
public void handleMessage(Message msg) {
if(msg.getData()!=null) {
switch (msg.getData().getString(Utils.INTENT_SERVICE_INVOKE)) {
case Utils.LOAD_All_DATA: {
saveActivities();
savePersons();
savePictureData();
Intent intent = new Intent(context, MainActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
Log.e("order", "forth");
break;
}
case Utils.READ_ACTIONS_DATA: {
readActionData();
break;
}
case Utils.READ_PERSONS_DATA: {
readPersonsData();
break;
}
}
}
stopSelf(msg.arg1);
}
}
#Override
public void onCreate() {
// Start up the thread running the service. Note that we create a
// separate thread because the service normally runs in the process's
// main thread, which we don't want to block. We also make it
// background priority so CPU-intensive work will not disrupt our UI.
HandlerThread thread = new HandlerThread("ServiceStartArguments");
thread.start();
// Get the HandlerThread's Looper and use it for our Handler
mServiceLooper = thread.getLooper();
mServiceHandler = new ServiceHandler(mServiceLooper);
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.e("service","service started");
Log.e("data",intent.getStringExtra(Utils.INTENT_SERVICE_INVOKE));
Bundle bundle = new Bundle();
bundle.putString(Utils.INTENT_SERVICE_INVOKE,intent.getStringExtra(Utils.INTENT_SERVICE_INVOKE));
// For each start request, send a message to start a job and deliver the
// start ID so we know which request we're stopping when we finish the job
Message msg = mServiceHandler.obtainMessage();
msg.arg1 = startId;
msg.setData(bundle);
mServiceHandler.sendMessage(msg);
// If we get killed, after returning from here, restart
return START_STICKY;
}
#Override
public void onDestroy() {
Toast.makeText(this, "service done", Toast.LENGTH_SHORT).show();
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
if these quires returning any values after insertion in database, then only you have to launch activity
saveActivities();
savePersons();
savePictureData();
try below code launch your activity inside Main thread handler
Handler handler = new Handler(Looper.getMainLooper());
handler.post(new Runnable() {
#Override
public void run() {
Intent intent = new Intent(context, MainActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
}
});
Related
In my app i am using a Service that periodically checks if there is a new personal message for the logged in user.
The service is started if the user enables the notification feature. Now if the user disables the notification feature i would like to stop the service.
I try to stop the service with the following lines of code.
Intent service = new Intent(getApplicationContext(), MessageService.class);
stopService(service);
The problem is that the service doesn't stop. It goes on working.
Here you can see my message service.
public class MessageService extends Service {
private int intervall;
public MessageService(){
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
super.onStartCommand(intent,flags,startId);
Bundle intentData = intent.getExtras();
if(intentData != null) {
this.intervall = intentData.getInt("intervall");
}
final Handler handler = new Handler(){
#Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
// async task for calling api otherwise we get an exeception here
new ServiceMessagesTask().execute(MessageService.this);
}
};
new Thread(new Runnable(){
public void run() {
while(true)
{
try {
Thread.sleep(intervall); // repeat after given intervall
handler.sendEmptyMessage(0);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}).start();
return START_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
}
}
I have an activity where the user can edit his preferences. There it is also possible to activate the notification feature.
The notification service is started or stoped in the savePreferences() method:
public void savePreferences(View button) {
EditText login = (EditText)findViewById(R.id.txtbLogin);
EditText password = (EditText)findViewById(R.id.txtbPassword);
CheckBox enableNotification = (CheckBox) findViewById(R.id.cbNotifications);
Spinner spinner = (Spinner) findViewById(R.id.notificationInterval);
if(!login.getText().equals("") && !password.getText().equals("")){
Map<String, Object> preferences = new HashMap<String, Object>();
preferences.put("document_type", CouchbaseHelper.CB_VIEW_USER_PREFERENCES);
preferences.put("login", login.getText().toString());
preferences.put("password", password.getText().toString());
if(enableNotification.isChecked()){
preferences.put("enableNotification", true);
} else {
preferences.put("enableNotification", false);
}
preferences.put("notificationInterval", this.notificationInterval);
CouchbaseHelper couchbaseHelper = new CouchbaseHelper(getApplicationContext());
String documentId = couchbaseHelper.createDocUserPreferences(preferences);
couchbaseHelper.closeDb();
// start notification service if enabled
if(enableNotification.isChecked()){
Intent service = new Intent(getApplicationContext(), MessageService.class);
service.putExtra("intervall", Integer.valueOf(this.notificationInterval)*60*1000);
startService(service);
} else {
// TODO: this is not working!!! service doesnt stop
// try to stop running service
if(isMyServiceRunning()){
Intent service = new Intent(getApplicationContext(), MessageService.class);
stopService(service);
}
}
}
finish();
Intent main = new Intent(Preferences.this, Main.class);
startActivity(main);
}
I'm afraid you really don't get what a service is, service is just a component that do not require UI and is not linked to an activity life cycle, hence it runs in background, BUT background doesn't necessarily means in a separate thread, actually the service runs in the main thread, now that's one thing, killing a service doesn't mean you are killing all the working threads you create within, and in your code you are creating a Thread that is looping forever, that thread although created in the service is not linked in any way to the service life cycle.
So, if you want to stop the thread, get a reference to the thread you are creating in the startCommand method and in the onDestroy method just stop it, instead of having a while(true) validation, go for a flag and just change it to false in the onDestroy so it will stop the thread you created when started the service.
Regards!
the service is started by a single activity 4 times, how many threads are created by a service? And if service is started by 4 different activities then how many threads are created? Which function must be implemented inside a service inherited from intentService? how many threads are required to create inside this function?
public class HelloService extends Service {
private Looper mServiceLooper;
private ServiceHandler mServiceHandler;
// Handler that receives messages from the thread
private final class ServiceHandler extends Handler {
public ServiceHandler(Looper looper) {
super(looper);
}
#Override
public void handleMessage(Message msg) {
long endTime = System.currentTimeMillis() + 5*1000;
while (System.currentTimeMillis() < endTime) {
synchronized (this) {
try {
wait(endTime - System.currentTimeMillis());
} catch (Exception e) {
}
}
}
// Stop the service using the startId, so that we don't stop
// the service in the middle of handling another job
stopSelf(msg.arg1);
}
}
#Override
public void onCreate() {
HandlerThread thread = new HandlerThread("ServiceStartArguments",
Process.THREAD_PRIORITY_BACKGROUND);
thread.start();
mServiceLooper = thread.getLooper();
mServiceHandler = new ServiceHandler(mServiceLooper);
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Toast.makeText(this, "service starting", Toast.LENGTH_SHORT).show();
Message msg = mServiceHandler.obtainMessage();
msg.arg1 = startId;
mServiceHandler.sendMessage(msg);
// If we get killed, after returning from here, restart
return START_STICKY;
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onDestroy() {
Toast.makeText(this, "service done", Toast.LENGTH_SHORT).show();
}
}
the service is started by a single activity 4 times, how many threads are created by a service?
Depends. Your Service creates a new thread in onCreate, so if it's never killed then you'll only have 1 thread created. If somehow it did get killed, you would end up with one for every time you started your Service.
And if service is started by 4 different activities then how many threads are created?
Same as above.
Which function must be implemented inside a service inherited from intentService?
You might try reading the docs for IntentService, you'd find you want to implement onHandleIntent.
how many threads are required to create inside this function?
Zero.
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() {...});
I am trying to send a message to my main activity from an Async task embedded within a Service. Basically, the Async task has to block on input and it can't run in the main Activity thread (the blocking was removed from the example code below). When the data comes in though, I need to send it to the main activity. I am finding that the messages sent below never make it. If the answer is moving the bind within the Async task, how do you do that? Pointing to example code would be a big help if possible.
public class InputService2 extends Service {
int bufferSize = 1024;
Process process;
DataInputStream os;
TextView inputView;
byte[] buffer = new byte[bufferSize];
private MyAsyncTask inputTask = null;
public void onCreate(){
inputTask = new MyAsyncTask();
inputTask.execute((Void[])null);
}
private class MyAsyncTask extends AsyncTask<Void,Void,Void> {
int mValue = 0;
static final int MSG_SET_VALUE = 3;
protected void onProgressUpdate(Void progress){
}
protected void onPostExecute(Void result) {
}
protected Void doInBackground(Void... params) {
int i = 0;
try {
mValue = 0x23;
Message message = Message.obtain(null,MSG_SET_VALUE,mValue,0);
mMessenger.send(message);
}
catch (Exception e) {
}
}
}
class IncomingHandler extends Handler {
#Override
public void handleMessage(Message msg) {
}
}
final Messenger mMessenger = new Messenger(new IncomingHandler());
public IBinder onBind(Intent intent) {
return mMessenger.getBinder();
}
}
Below is inside the activity:
class IncomingHandler extends Handler {
#Override
public void handleMessage(Message msg) {
Context context = getApplicationContext();
int duration = Toast.LENGTH_LONG;
Toast toast = Toast.makeText(context, msg.arg1, duration);
toast.show();
}
}
boolean mBound;
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 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.
mService = new Messenger(service);
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.
mService = null;
mBound = false;
}
};
protected void onStart() {
super.onStart();
// Bind to the service
bindService(new Intent(this, InputService2.class), mConnection,
Context.BIND_AUTO_CREATE);
}
It looks like you based your example on the javadoc reference at http://developer.android.com/reference/android/app/Service.html#RemoteMessengerServiceSample, however you left out much of the implementation detail that actually makes it work. You have to go back and implement the full functionality referenced in that example to use that particular pattern: pay careful attention to the REGISTER_CLIENT and UN_REGISTER_CLIENT implementation sections in the IncomingHandler class as these are the bits that actually ensure that the Message can be transferred from the Service to the Activity.
I am developing an Android app and I am doing some heavy work (bringing data from an online web page and parsing it to store in database) in a service. Currently, it is taking about 20+ mins and for this time my UI is stuck. I was thinking of using a thread in service so my UI doesn't get stuck but it is giving error. I am using the following code:
Thread thread = new Thread()
{
#Override
public void run() {
try {
while(true) {
sleep(1000);
Toast.makeText(getBaseContext(), "Running Thread...", Toast.LENGTH_LONG).show();
}
} catch (InterruptedException e) {
Toast.makeText(getBaseContext(), e.toString(), Toast.LENGTH_LONG).show();
}
}
};
thread.start();
This simple code is giving run time error. Even If I take out the while loop, it is still not working.
Please, can any one tell me what mistake I am doing. Apparently, I copied this code directly from an e-book. It is suppose to work but its not.
Android commandment: thou shall not interact with UI objects from your own threads
Wrap your Toast Display into runOnUIThread(new Runnable() { });
Example of new thread creation taken from Android samples (android-8\SampleSyncAdapter\src\com\example\android\samplesync\client\NetworkUtilities.java):
public static Thread performOnBackgroundThread(final Runnable runnable) {
final Thread t = new Thread() {
#Override
public void run() {
try {
runnable.run();
} finally {
}
}
};
t.start();
return t;
}
runnable is the Runnable that contains your Network operations.
You can use HandlerThread and post to it, here is an example to service that has one.
public class NetworkService extends Service {
private HandlerThread mHandlerThread;
private Handler mHandler;
private final IBinder mBinder = new MyLocalBinder();
#Override
public void onCreate() {
super.onCreate();
mHandlerThread = new HandlerThread("LocalServiceThread");
mHandlerThread.start();
mHandler = new Handler(mHandlerThread.getLooper());
}
public void postRunnable(Runnable runnable) {
mHandler.post(runnable);
}
public class MyLocalBinder extends Binder {
public NetworkService getService() {
return NetworkService.this;
}
}
#Override
public IBinder onBind(Intent intent) {
return mBinder;
}
}
You may define your jobs in a runnable object, use a thread object for running it and start this thread in your service's onStartCommand() function. Here is my notes:
In your service class:
define your main loop in an Runnable object
create Thread object with the runnable object as parameter
In your service class's onStartCommand method():
call thread object's start function()
my code :
private Runnable busyLoop = new Runnable() {
public void run() {
int count = 1;
while(true) {
count ++;
try {
Thread.sleep(100);
} catch (Exception ex) {
;
}
ConvertService.running.sendNotification("busyLoop" + count);
}
}
};
public int onStartCommand(Intent intent, int flags, int startId) {
sendNotification("onStartCommand");
if (! t.isAlive()) {
t.start();
}
return START_STICKY;
}