Intent Service Example

MainActivity.java

public class MainActivity extends AppCompatActivity
{
    private ResponseReceiver receiver;

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


        Intent msgIntent = new Intent(this, MyCustomService.class);
        msgIntent.putExtra(MyCustomService.PARAM_IN_MSG, "Hello from main activity");
        startService(msgIntent);


        IntentFilter filter = new IntentFilter(ResponseReceiver.ACTION_RESP);
        filter.addCategory(Intent.CATEGORY_DEFAULT);
        receiver = new ResponseReceiver();
        registerReceiver(receiver, filter);
    }



    public class ResponseReceiver extends BroadcastReceiver
    {
        public static final String ACTION_RESP =
                "MESSAGE_PROCESSED";

        @Override
        public void onReceive(Context context, Intent intent) {

            String text = intent.getStringExtra(MyCustomService.PARAM_OUT_MSG);
            Log.d( "TAG", "onReceive: "+text );
        }
    }

}

MyCustomService.java

public class MyCustomService extends IntentService
{

    public static final String PARAM_IN_MSG = "imsg";
    public static final String PARAM_OUT_MSG = "omsg";

    public MyCustomService( )
    {
        super( "MyCustomService" );
    }



    public MyCustomService( String name )
    {
        super( "MyCustomService" );
    }

    @Override protected void onHandleIntent( Intent intent )
    {
        String msg = intent.getStringExtra( PARAM_IN_MSG );

        SystemClock.sleep( 10000 ); // 30 seconds


        String resultTxt = msg + " "
                + DateFormat.format( "MM/dd/yy h:mmaa", System.currentTimeMillis() );

        Log.d( msg, resultTxt );

        Intent broadcastIntent = new Intent();
        broadcastIntent.setAction( MainActivity.ResponseReceiver.ACTION_RESP );
        broadcastIntent.addCategory( Intent.CATEGORY_DEFAULT );
        broadcastIntent.putExtra( PARAM_OUT_MSG, resultTxt );
        sendBroadcast( broadcastIntent );
    }


}

Refer to this link for bound services in Android.