SharedPreferences result in debugger error

Question

I just wrote this simple piece of code, but it doesn't work, but the debugger stopped my program. Any ideas? This is the line that probably causes the error: SharedPreferences.Editor editor = sharedPreferences.edit();

package com.***.juraquiz;

import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class FragmentStatistics extends Fragment {

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){

    int answers_total;
    int correct_answers_total;
    int wrong_answers_total;


    SharedPreferences sharedPreferences = getSharedPreferences("statistics", Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPreferences.edit();
    editor.putInt("ANSWERS_TOTAL", 90);
    editor.putInt("CORRECT_ANSWERS_TOTAL", 82);
    editor.commit();

    View view = inflater.inflate(R.layout.fragment_statistics, container, false);

    SupportFunctions.setViewBackgroundWithDrawable(view.findViewById(R.id.tv_heading_statistics), getResources().getDrawable(R.drawable.quiz_heading_background));

    TextView tv_answers_round = (TextView)view.findViewById(R.id.tv_answers_round_value);
    tv_answers_round.setText(String.valueOf(Globals.getANSWERS_ROUND()));

    TextView tv_correct_answers_round = (TextView)view.findViewById(R.id.tv_correct_answers_round_value);
    tv_correct_answers_round.setText(String.valueOf(Globals.getCORRECT_ANSWERS_ROUND()));

    TextView tv_wrong_answers_round = (TextView)view.findViewById(R.id.tv_wrong_answers_round_value);
    tv_wrong_answers_round.setText(String.valueOf(Globals.getANSWERS_ROUND()-Globals.getCORRECT_ANSWERS_ROUND()));

    SharedPreferences getSharedPreferences = getSharedPreferences("statistics", Context.MODE_PRIVATE);
    answers_total = getSharedPreferences.getInt("ANSWERS_TOTAL", 0);
    correct_answers_total = getSharedPreferences.getInt("CORRECT_ANSWERS_TOTAL", 0);
    wrong_answers_total = answers_total - correct_answers_total;

    TextView tv_answers_total = (TextView)view.findViewById(R.id.tv_answers_total_value);
    tv_answers_total.setText(String.valueOf(answers_total));

    TextView tv_correct_answers_total = (TextView)view.findViewById(R.id.tv_correct_answers_total_value);
    tv_correct_answers_total.setText(String.valueOf(correct_answers_total));

    TextView tv_wrong_answers_total = (TextView)view.findViewById(R.id.tv_wrong_answers_total_value);
    tv_wrong_answers_total.setText(String.valueOf(wrong_answers_total));

    return view;

}

private SharedPreferences getSharedPreferences(String string,
        int modePrivate) {
    // TODO Auto-generated method stub
    return null;
}

}

This is what I get:

Pick [Android Application]

Pick [Android Application]
Pick [Android Application]
Pick [Android Application]
DalvikVM [localhost:8600] Pick [Android Application]
DalvikVM [localhost:8600]
Thread [<1> main] (Suspended (exception NullPointerException))

FragmentStatistics.onCreateView(LayoutInflater, ViewGroup, Bundle) line: 22 FragmentStatistics(Fragment).performCreateView(LayoutInflater, ViewGroup, Bundle) line: 1500
FragmentManagerImpl.moveToState(Fragment, int, int, int, boolean) line: 927 FragmentManagerImpl.moveToState(int, int, int, boolean) line: 1104
BackStackRecord.run() line: 682 FragmentManagerImpl.execPendingActions() line: 1467 FragmentManagerImpl$1.run() line: 440
Handler.handleCallback(Message) line: 730
FragmentActivity$1(Handler).dispatchMessage(Message) line: 92
Looper.loop() line: 137 ActivityThread.main(String[]) line: 5419
Method.invokeNative(Object, Object[], Class, Class[], Class, int, boolean) line: not available [native method]
Method.invoke(Object, Object...) line: 525
ZygoteInit$MethodAndArgsCaller.run() line: 1187 ZygoteInit.main(String[]) line: 1003
NativeStart.main(String[]) line: not available [native method]
Thread [<10> Binder_2] (Running)
Thread [<9> Binder_1] (Running) Thread [<11> Binder_3] (Running)

Nathan Walters Nathan Walters · Accepted Answer · 2014-03-22T03:32:58

I'm not sure why, but you have a private method called getSharedPreferences(...). This overrides the default Android getSharedPreferences(...). When you call your own getSharedPreferences(...), you return null, and trying to do anything on that object will obviously throw a NPE.

SharedPreferences result in debugger error

1 Answers