AIDL client

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private static final String SERVER_PACKAGE = "com.jaeryong.android.aidlserver";

    private static final String SERVER_ACTION = "com.jaeryong.android.action.aidlserver";

    private IRemoteService mRemoteService;

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

        Intent serviceIntent = new Intent(SERVER_ACTION);
        serviceIntent.setPackage(SERVER_PACKAGE);
        bindService(serviceIntent, serviceConnection, Context.BIND_AUTO_CREATE);

        Button button = (Button)findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try {
                    int sum = mRemoteService.sum(2, 5);
                    Toast.makeText(getApplicationContext(), String.valueOf(sum), Toast.LENGTH_SHORT).show();
                } catch (RemoteException e) {
                    e.printStackTrace();
                }
            }
        });
    }

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

    private ServiceConnection serviceConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            mRemoteService = IRemoteService.Stub.asInterface(service);
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            mRemoteService = null;
        }
    };

}