Unable to start service Intent, U=0: not found

Question

I have been struggling for two days on this issue. I have two apps and trying to communicate by Messenger IPC but it even't failed to bind to server app's service.

--- server side

    <service android:name="com.example.RemoteService" android:exported="true">
    </service>
</application>

-- client side

@Override
protected void onCreate(Bundle savedInstanceState) {
             :
     this.connection = new RemoteServiceConnection();

@Override
public void onStart() {
           :
     Intent intent = new Intent();
    intent.setClassName("com.example.client", "com.example.RemoteService");
    //Intent i = new Intent("com.example.RemoteService");
    //i.setPackage(this.getPackageName());
    boolean ret = bindService(intent , this.connection, Context.BIND_AUTO_CREATE);

ret is always false and always receives system message W/ActivityManagerService: Unable to start service Intent { act=com.example.RemoteService pkg=com.example.client } U=0: not found

It seems everything ok for implementation. I feel like it's under layer issue. Please help.

Thanks

Here's Service Class

public class RemoteService extends Service
{
    private Messenger messenger; //receives remote invocations
    @Override
    public IBinder onBind(Intent intent)
    {
        if(this.messenger == null)
        {
            synchronized(RemoteService.class)
            {
                if(this.messenger == null)
                {
                    this.messenger = new Messenger(new IncomingHandler());
                }
            }
        }
        //Return the proper IBinder instance
        return this.messenger.getBinder();
    }

    private class IncomingHandler extends Handler
    {
        @Override
        public void handleMessage(Message msg)
        {
            System.out.println("*****************************************");
            System.out.println("Remote Service successfully invoked!!!!!!");
            System.out.println("*****************************************");

            int what = msg.what;

            Toast.makeText(RemoteService.this.getApplicationContext(), "Remote Service invoked-("+what+")", Toast.LENGTH_LONG).show();

            //Setup the reply message
            Message message = Message.obtain(null, 2, 0, 0);
            try
            {
                //make the RPC invocation
                Messenger replyTo = msg.replyTo;
                replyTo.send(message);
            }
            catch(RemoteException rme)
            {
                //Show an Error Message
                Toast.makeText(RemoteService.this, "Invocation Failed!!", Toast.LENGTH_LONG).show();
            }
        }
    }
}

Answer 1

try to start your service like this

startService(new Intent(this, YourService.class));

don't forget to add your service in your manifest,

<application>

    <service
        android:name=".MyService"
         >
    </service>

</application>

Answer 2

Some times, if you can not find any wrong in code, you could try reboot device. May be resolve this problem.

Answer 3

setClassName takes the package name and class name as the parameters:

intent.setClassName("com.example.client", "com.example.RemoteService");

If you package name is com.example.client then class name should be either RemoteService or com.example.client.RemoteService

Also you can check if the package appears under: /data/data/com.example....

This error occurs only because the package/class is not found

Answer 4

After recent changes, You can use \<queries> \<package android:name ="your package name" /> \</queries>

https://developer.android.com/training/package-visibility/declaring