I have changed the  ip in the code
		String chs_username = "hw1"; String chs_password = "hw1";
		String[] stringUrl = {"http://192.168.43.57:8080/chs/api/topics/publisher?username="+chs_username+"&pass="+chs_password,
				"http://192.168.43.57:8080/chs/api/topics/subscriber?username="+chs_username+"&pass="+chs_password,
		};


still getting this
log

 FATAL EXCEPTION: main
                                                 Process: com.iiitd.navigationexample, PID: 6078
                                                 java.lang.RuntimeException: Unable to create service com.iiitd.amqp.AMQPService: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference
                                                     at android.app.ActivityThread.handleCreateService(ActivityThread.java:2801)
                                                     at android.app.ActivityThread.access$1800(ActivityThread.java:155)
                                                     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1400)
                                                     at android.os.Handler.dispatchMessage(Handler.java:102)
                                                     at android.os.Looper.loop(Looper.java:135)
                                                     at android.app.ActivityThread.main(ActivityThread.java:5343)
                                                     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:905)
                                                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)
                                                  Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference
                                                     at android.widget.Toast.<init>(Toast.java:101)
                                                     at android.widget.Toast.makeText(Toast.java:258)
                                                     at com.iiitd.amqp.AMQPService.onCreate(AMQPService.java:102)
                                                     at android.app.ActivityThread.handleCreateService(ActivityThread.java:2791)
                                                     at android.app.ActivityThread.access$1800(ActivityThread.java:155)
                                                     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1400)
                                                     at android.os.Handler.dispatchMessage(Handler.java:102)
                                                     at android.os.Looper.loop(Looper.java:135)
                                                     at android.app.ActivityThread.main(ActivityThread.java:5343)
                                                     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:905)
                                                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)



and the line is

at com.iiitd.amqp.AMQPService.onCreate(AMQPService.java:102)

if (networkInfo != null && networkInfo.isConnected()) {
			new DownloadWebpageTask().execute(stringUrl);
		} else {
			Toast.makeText(mContext, "No network connection available!!", Toast.LENGTH_LONG).show();
		}