How to Get Data from Service to Activity

How to get data from service to activity

In my Service class I wrote this

private static void sendMessageToActivity(Location l, String msg) {
    Intent intent = new Intent("GPSLocationUpdates");
    // You can also include some extra data.
    intent.putExtra("Status", msg);
    Bundle b = new Bundle();
    b.putParcelable("Location", l);
    intent.putExtra("Location", b);
    LocalBroadcastManager.getInstance(context).sendBroadcast(intent);
}

and at the Activity side we have to receive this Broadcast message

LocalBroadcastManager.getInstance(getActivity()).registerReceiver(
            mMessageReceiver, new IntentFilter("GPSLocationUpdates"));

By this way you can send message to an Activity.
here mMessageReceiver is the class in that class you will perform what ever you want....

in my code I did this....

private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        // Get extra data included in the Intent
        String message = intent.getStringExtra("Status");
        Bundle b = intent.getBundleExtra("Location");
        lastKnownLoc = (Location) b.getParcelable("Location");
        if (lastKnownLoc != null) {
            tvLatitude.setText(String.valueOf(lastKnownLoc.getLatitude()));
            tvLongitude
                    .setText(String.valueOf(lastKnownLoc.getLongitude()));
            tvAccuracy.setText(String.valueOf(lastKnownLoc.getAccuracy()));
            tvTimestamp.setText((new Date(lastKnownLoc.getTime())
                    .toString()));
            tvProvider.setText(lastKnownLoc.getProvider());
        }
        tvStatus.setText(message);
        // Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
    }
};

How to send data from service to activity?

Use a messenger to send the Message from the Service on onHandleIntent() method, then Recieve it with A handler...see this tutorial http://www.vogella.com/articles/AndroidServices/article.html

How to safely send data from a service to running activity

Q: How do I send data from an Android service to my activity?

A: You have several alternatives:

1. Use intents:

How to get data from service to activity

Send msg from service:

private static void sendMessageToActivity(Location l, String msg) {
    Intent intent = new Intent("GPSLocationUpdates");
    // You can also include some extra data.
    intent.putExtra("Status", msg);
    Bundle b = new Bundle();
    b.putParcelable("Location", l);
    intent.putExtra("Location", b);
    LocalBroadcastManager.getInstance(context).sendBroadcast(intent);

Register to receive message in activity:

LocalBroadcastManager.getInstance(getActivity()).registerReceiver(
            mMessageReceiver, new IntentFilter("GPSLocationUpdates"));

Custom message receiver in activity:

private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        // Get extra data included in the Intent
        String message = intent.getStringExtra("Status");
        Bundle b = intent.getBundleExtra("Location");
        lastKnownLoc = (Location) b.getParcelable("Location");
        ...

I would NOT characterize this as "unsafe" - it can be a perfectly reasonable approach.

2. Have the activity bind to the service

https://developer.android.com/guide/components/bound-services

Service:

public class LocalService extends Service {
    // Binder given to clients
    private final IBinder binder = new LocalBinder();
    ...
public class LocalBinder extends Binder {
        LocalService getService() {
            // Return this instance of LocalService so clients can call public methods
            return LocalService.this;
        }
    }

    @Override
    public IBinder onBind(Intent intent) {
        return binder;
    }

Activity:

@Override
    protected void onStart() {
        super.onStart();
        // Bind to LocalService
        Intent intent = new Intent(this, LocalService.class);
        bindService(intent, connection, Context.BIND_AUTO_CREATE);
        ...
     @Override
        protected void onStop() {
            super.onStop();
            unbindService(connection);
            mBound = false;
        ...
    /** Defines callbacks for service binding, passed to bindService() */
        private ServiceConnection connection = new ServiceConnection() {

        @Override
        public void onServiceConnected(ComponentName className,
                IBinder service) {
            // We've bound to LocalService, cast the IBinder and get LocalService instance
            LocalBinder binder = (LocalBinder) service;
            mService = binder.getService();
            mBound = true;
        }
    ...
    // To use the service, your client would call mService.someMethod()...            

I'm not sure exactly what you're looking for, but example 1 is probably your best bet.

Here's a tutorial that might help give you more details/more ideas:

Basics Of Services In Android:

• Part 1: Basics
• Part 2: Binding services to an activity
• Part 3: Using Messenger

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https://developer.android.com/guide/components/broadcasts

Android provides three ways for apps to send broadcast:

• The sendOrderedBroadcast(Intent, String) method sends broadcasts to one receiver at a time.
• sendBroadcast(Intent) method sends broadcasts to all receivers in an undefined order. This is called a Normal Broadcast. This is more
  efficient, but means that receivers cannot read results from other
  receivers, propagate data received from the broadcast, or abort the
  broadcast.
• LocalBroadcastManager.sendBroadcast method sends broadcasts to receivers that are in the same app as the sender. If you don't need to
  send broadcasts across apps, use local broadcasts. The implementation
  is much more efficient (no interprocess communication needed) and you
  don't need to worry about any security issues related to other apps
  being able to receive or send your broadcasts.

Additionally:

https://developer.android.com/guide/components/broadcasts#restrict-broadcasts-permissions

Restricting broadcasts with permissions

Permissions allow you to restrict broadcasts to the set of apps that hold certain permissions. You can enforce restrictions on either
the sender or receiver of a broadcast.

Sending with permissions

When you call sendBroadcast(Intent, String) or sendOrderedBroadcast(Intent, String, BroadcastReceiver, Handler, int,
String, Bundle), you can specify a permission parameter. Only
receivers who have requested that permission with the tag in their
manifest (and subsequently been granted the permission if it is
dangerous) can receive the broadcast. For example, the following code
sends a broadcast:

Personally, I don't see any "security" issue at all with simply using an intent.

But if you want or need to, you can use the above techniques to further lock down communications.

'Hope that helps!

Tranfer Data from service to activity

There is a many way,I say some of that:

1-Use store data in service (such as SharedPrefrences,DB and ...) and retrive in activity

2-Use eventbus or broadcast receivers

3-Use callback patern for callback data from service to activiy

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