bindService.java

public class LocalService extends Service {
 // Binder given to clients
 private final IBinder mBinder = new LocalBinder();
 // Random number generator
 private final Random mGenerator = new Random();

 /**
 * Class used for the client Binder. Because we know this service always
 * runs in the same process as its clients, we don't need to deal with IPC.
 */
 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 mBinder;
 }

 /** method for clients */
 public int getRandomNumber() {
 return mGenerator.nextInt(100);
 }
}

//start service

public class BindingActivity extends Activity {
 LocalService mService;
 boolean mBound = false;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.main);
 }

 @Override
 protected void onStart() {
 super.onStart();
 // Bind to LocalService
 Intent intent = new Intent(this, LocalService.class);
 bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
 }

 @Override
 protected void onStop() {
 super.onStop();
 // Unbind from the service
 if (mBound) {
 unbindService(mConnection);
 mBound = false;
 }
 }

 /** Called when a button is clicked (the button in the layout file attaches to
 * this method with the android:onClick attribute) */
 public void onButtonClick(View v) {
 if (mBound) {
 // Call a method from the LocalService.
 // However, if this call were something that might hang, then this request should
 // occur in a separate thread to avoid slowing down the activity performance.
 int num = mService.getRandomNumber();
 Toast.makeText(this, "number: " + num, Toast.LENGTH_SHORT).show();
 }
 }

 /** Defines callbacks for service binding, passed to bindService() */
 private ServiceConnection mConnection = 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;
 }

 @Override
 public void onServiceDisconnected(ComponentName arg0) {
 mBound = false;
 }
 };
}