Attempt to invoke virtual method on a null object reference Android Issue

Question

I am trying to make http request every 10 sec and then update my UI text with with current time, Below is the srvice class which is throwing this error -

public class MyService extends Service {
    Handler handler;
    MainActivity refer;

    public MyService(){

    }

    public MyService(Handler handle,MainActivity ref) {
        super();
        this.handler= handle;
        this.refer = ref;
        Log.i("MyService","=============Inside MyService=========");
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {

        new Handler().postDelayed(new Runnable() {
            public void run() {
                String res = makeRequest("www.ggggggg.com","Hello World");
                refer.update(res); // Update is main activity function
            }
        }, 10000);

            return START_STICKY;
        }


    @Override
    public IBinder onBind(Intent intent) {
       return null;
    }

    public static String makeRequest(String uri, String json) {
        Log.i("MyService","===============Inside makeRequest===================");
        try {
            HttpPost httpPost = new HttpPost(uri);
            httpPost.setEntity(new StringEntity(json));
            httpPost.setHeader("Accept", "application/json");
            httpPost.setHeader("Content-type", "application/json");
            //return new DefaultHttpClient().execute(httpPost);
            // Since dummy server so response will be null so hardcoding it to current time
            SimpleDateFormat df = new SimpleDateFormat("HH:mm:ss",Locale.getDefault());
            return (df.format(new Date()));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }  catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

}

Error is this ---

09-29 15:36:10.637 1797-1797/com.google.richa.testapp E/AndroidRuntime﹕ FATAL EXCEPTION: main Process: com.ttni.richa.ttnitestapp, PID: 1797 java.lang.NullPointerException: Attempt to invoke virtual method 'void com.ttni.google.testapp.MainActivity.update(java.lang.String)' on a null object reference at com.google.richa.testapp.MyService$1.run(MyService.java:40) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5221) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 09-29 15:41:10.685 1797-1797/com.google.richa.testapp I/Process﹕ Sending signal. PID: 1797 SIG: 9

You cannot communicate with your service and activity like this. see http://stackoverflow.com/questions/20594936/communication-between-activity-and-service — subhash, Sep 29 '15 at 10:29

Attempt to invoke virtual method on a null object reference Android Issue

0 Answers0