I can't find this NullPointerException

Question

I have an issue I need help with. I am running into a NullPointerException no matter what I do with this app, and at this point it is seriously holding up this project. I have reviewed the logcat multiple times, made changes and re run the app and every time it turns out a nullpointerexception. For the life of me I can't seem to figure out what is causing it. Can someone point out where it is, and if possible, why it occurred since as far as I can tell I have everything assigned a value.

GameStart.java:

package com.saphiric.simproject;

import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

/**
 * Created by Saphiric on 11/12/14.
 */
public class GameStart extends Activity {

    /**
     * Necessary activity variables
     */
    int clickCount = 0;
    TextView storyText;
    Button advanceGame;
    DecisionFragment decisionFragment;
    ControlsFragment controlsFragment;

    public View.OnClickListener decisionTime = new View.OnClickListener(){
        public void onClick(View v) {
            clickCount = clickCount + 1; // Increments clickCount by 1 per click

//            /**
//             * Will handle checking how far into the story the player is
//             * and update components as necessary.
//             */
//            switch (clickCount) {
//                case 1:
//                    storyText.setText(R.string.story_opening_two);
//                    break;
//
//                case 2:
//                    FragmentTransaction decisionTime = fragmentManager.beginTransaction();
//                    // Replace the fragment currently inside of the fragmentContainer
//                    decisionTime.replace(R.id.fragmentContainer, decisionFragment);
//                    decisionTime.commit();
//                    break;
//
//                default:
//                    System.out.println("An error occurred");
//            }
//            System.out.println(clickCount);
        }
    };

    /**
     * Android activity methods
     * @param savedInstanceState is the apps savedInstanceState
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_game_start);

        // UI element handles
        advanceGame = (Button) findViewById(R.id.advanceButton);
        storyText = (TextView) findViewById(R.id.storyText);

        decisionFragment = new DecisionFragment();
        controlsFragment = new ControlsFragment();

        FragmentManager fragmentManager = getFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

        // UI will add the ControlsFragment in it's starting state for that activity.
        fragmentTransaction.add(R.id.fragmentContainer, controlsFragment).commit();

        // Sets the advanceButton to run decisionTime method
        advanceGame.setOnClickListener(decisionTime);
    }
}

LogCat:

12-07 13:16:10.142  19915-19915/com.saphiric.simproject E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.saphiric.simproject, PID: 19915
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.saphiric.simproject/com.saphiric.simproject.GameStart}: java.lang.NullPointerException
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2596)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2653)
            at android.app.ActivityThread.access$800(ActivityThread.java:156)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1355)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:157)
            at android.app.ActivityThread.main(ActivityThread.java:5872)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1069)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:885)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
            at com.saphiric.simproject.GameStart.onCreate(GameStart.java:75)
            at android.app.Activity.performCreate(Activity.java:5312)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1111)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2552)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2653)
            at android.app.ActivityThread.access$800(ActivityThread.java:156)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1355)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:157)
            at android.app.ActivityThread.main(ActivityThread.java:5872)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1069)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:885)
            at dalvik.system.NativeStart.main(Native Method)

WHich XML file, the fragment I'm trying to lay into the container or the one for the activity itself — Saphiric, Dec 07 '14 at 18:24

score 3 · Accepted Answer · answered Dec 07 '14 at 18:24

3

The null pointer happens at line 75 , i.e.

advanceGame.setOnClickListener(decisionTime);

Here, the only thing that can be null is advanceGame. This means that

advanceGame = (Button) findViewById(R.id.advanceButton);

is not able to find your button from your view. Check the id of the button if its exactly the same as you defined it in your android xml.

answered Dec 07 '14 at 18:24

Antrromet

15,294
10
60
75

So if the id is assigned in the One.xml, and the layout for Activity2 is activity2.xml, then the id wont be found for the activity, resulting in the NullPointer, am I understanding that right? – Saphiric Dec 07 '14 at 18:28
Problem solved thank you. It led to another issue but I'll handle that separately. Much appreciated – Saphiric Dec 07 '14 at 19:42

score 1 · Answer 2 · answered Dec 07 '14 at 18:22

1

I believe that advanceGame is null.

You can't find button by findViewById(R.id.advanceButton);

answered Dec 07 '14 at 18:22

DontRelaX

744
4
10

Console Logging this now to check one moment – Saphiric Dec 07 '14 at 18:25

score 0 · Answer 3 · answered Dec 07 '14 at 18:26

NPE is at line 75

advanceGame.setOnClickListener(decisionTime);

it is clear from

at com.saphiric.simproject.GameStart.onCreate(GameStart.java:75)

Looks like at

advanceGame = (Button) findViewById(R.id.advanceButton);

view was not found. You can debug that or add check at 75

if(null != advanceGame) advanceGame = (Button) findViewById(R.id.advanceButton);

score 0 · Answer 4 · answered Dec 07 '14 at 18:27

0

I think just check @+id of your activity_game_start.xml layout of advanceGame button it might have different name

answered Dec 07 '14 at 18:27

sandy

203
1
7

I can't find this NullPointerException

4 Answers4