Android app running in emulator but not in android device

Question

I have tried for whole day fixing this problem with relevant research. I am able to run my application in emulator but not in android device ie samsung galaxy ace 2. I got following as error in logcat. Your help is really appreciated. Thank you!

03-20 18:40:07.340: E/AndroidRuntime(15785): FATAL EXCEPTION: main
03-20 18:40:07.340: E/AndroidRuntime(15785): java.lang.NullPointerException
03-20 18:40:07.340: E/AndroidRuntime(15785):    at com.dorji.finalproject.LoginLayout$MyAsyncTask.onPostExecute(LoginLayout.java:87)
03-20 18:40:07.340: E/AndroidRuntime(15785):    at com.dorji.finalproject.LoginLayout$MyAsyncTask.onPostExecute(LoginLayout.java:1)
03-20 18:40:07.340: E/AndroidRuntime(15785):    at android.os.AsyncTask.finish(AsyncTask.java:417)
03-20 18:40:07.340: E/AndroidRuntime(15785):    at android.os.AsyncTask.access$300(AsyncTask.java:127)
03-20 18:40:07.340: E/AndroidRuntime(15785):    at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:429)
03-20 18:40:07.340: E/AndroidRuntime(15785):    at android.os.Handler.dispatchMessage(Handler.java:99)
03-20 18:40:07.340: E/AndroidRuntime(15785):    at android.os.Looper.loop(Looper.java:130)
03-20 18:40:07.340: E/AndroidRuntime(15785):    at android.app.ActivityThread.main(ActivityThread.java:3691)
03-20 18:40:07.340: E/AndroidRuntime(15785):    at java.lang.reflect.Method.invokeNative(Native Method)
03-20 18:40:07.340: E/AndroidRuntime(15785):    at java.lang.reflect.Method.invoke(Method.java:507)
03-20 18:40:07.340: E/AndroidRuntime(15785):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:912)
03-20 18:40:07.340: E/AndroidRuntime(15785):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:670)
03-20 18:40:07.340: E/AndroidRuntime(15785):    at dalvik.system.NativeStart.main(Native Method)

Main error code:

     @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            new newAsyncTask().execute();
        }
    });
}

private class newAsyncTask extends AsyncTask<Void, Void, Void>
{
        ProgressDialog Dialog;
        String user = username.getText().toString();
        String pass = password.getText().toString();



        @Override
        protected void onPreExecute() {
                Dialog = ProgressDialog.show(Login.this, "processing..", "data is Loading...");
        }


        @Override
                protected void onPostExecute(Void result) {
                    if(res.equals("1")){
                        if (Dialog.isShowing()) {
                        Dialog.dismiss();
                        }

                } else{
                        error.setText("Sorry, wrong username and password");
                        Dialog.dismiss();
                }
                }

        @Override
        protected Void doInBackground(Void... params) {


             ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
             postParameters.add(new BasicNameValuePair("username", user));
             postParameters.add(new BasicNameValuePair("password", pass));

                String response = null;
                try {
                    response = CustomHttpClient.executeHttpPost("http://10.0.2.2:8080/MainServer/LoginResponse", postParameters);
                    res=response.toString();
                    res= res.replaceAll("\\s+","");
                    Bundle bundle = new Bundle();
                    bundle.putString("param1", user);
                    bundle.putString("param2", pass);

                    Intent newIntent = new Intent(getApplicationContext(), MainActivity.class);
                    newIntent.putExtras(bundle);
                    startActivityForResult(newIntent, 0);

                        } catch (Exception e) {
                            System.out.println(e.toString());
                            }
                        return null;
                        }
        }

Answer 1

Your device can not access "10.0.2.2:8080" so you get into the exception and return null from doInBackground. In onPostExecute you try to run method equals() on null, and get a null pointer exception