Android Bind Service with Messenger

Android Bind Service with Messenger

Hi All, 

This example shows how we can bind a service and communicate via Handler.

Following is the Activity,

package com.aidl.messenger;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Looper;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
import android.widget.Toast;

public class AIDLMessengerActivity extends Activity {
 /** Called when the activity is first created. */
 private Messenger messenger;
 private MyServiceConnection conn;
 final Messenger mMessenger = new Messenger(new IncomingHandler());
 
 class IncomingHandler extends Handler{
  @Override
  public void handleMessage(Message msg) {
   super.handleMessage(msg);
   switch(msg.what){
   case 2:
    Bundle bundle = msg.getData();
    Toast.makeText(AIDLMessengerActivity.this, bundle.getString("reply"), Toast.LENGTH_SHORT).show();
    break;
   }
  }
 }
 
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  // intent.setClassName("com.aidl.messenger",
  // "com.aidl.messenger.MyService");
  conn = new MyServiceConnection();
  boolean mIsBound = bindService(new Intent(this, MyService.class), conn,
    Context.BIND_AUTO_CREATE);
 }

 @Override
 protected void onDestroy() {
  unbindService(conn);
  super.onDestroy();
 }

 class MyServiceConnection implements ServiceConnection {

  @Override
  public void onServiceConnected(ComponentName arg0, IBinder binder) {
   messenger = new Messenger(binder);
   Message msg = Message.obtain(null, MyService.MESSAGE_TEST, 0, 0);
   Bundle bundle = new Bundle();
   bundle.putString("name", "Jihad");
   msg.setData(bundle);
   msg.replyTo = mMessenger;
   try {
    messenger.send(msg);
   } catch (RemoteException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
  }

  @Override
  public void onServiceDisconnected(ComponentName arg0) {
   messenger = null;
  }

 }
}

and the Service is, 

package com.aidl.messenger;

import android.app.Service;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
import android.widget.Toast;

public class MyService extends Service {

 public static final int MESSAGE_TEST = 1;
 public static final int MESSAGE_TEST_REPLY = 2;
 private Messenger mMessenger = null;
 private String mesg = "";
 class MyHandler extends Handler {
  @Override
  public void handleMessage(Message msg) {
   super.handleMessage(msg);
   switch (msg.what) {
   case MESSAGE_TEST:
    mesg = "Hi ";
    Toast.makeText(MyService.this, "received in service", Toast.LENGTH_SHORT).show();
    mMessenger = msg.replyTo;
    try {
     Bundle bundle = msg.getData();
     String name = bundle.getString("name");
     Message newMsg = new Message();
     newMsg.what = MESSAGE_TEST_REPLY;
     bundle.clear();
     bundle.putString("reply", mesg +name+", Welcome to Service");
     newMsg.setData(bundle);
     mMessenger.send(newMsg);
    } catch (RemoteException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
    break;

   default:
    break;
   }
  }
 }
 
 public void testMethod(){
  Toast.makeText(MyService.this, "Test method", Toast.LENGTH_SHORT).show();
 }

 private Messenger messenger = new Messenger(new MyHandler());

 @Override
 public IBinder onBind(Intent intent) {
  return messenger.getBinder();
 }

}

and Manifest,

In Activity, We have one Messenger associated with a Handler. This is for handling the message from the service.

In Service, the Messenger will handle the request from the activity.

Thanks,