NullPointerException when onReceive is callled for BroadcastReceiver

Question

I am receiving a NullPointerException when I use my BroadcastReceiver to get a Boolean value back to determine whether or not an ImageButton will be used. I have no idea why and all of the tutorials I have looked at are not helping.

here is my code calling the service and calling onReceive

    //start full day timer service for natural disasters
    startService(new Intent(runGraphics.this, NaturalDisaster.class));

    //stop full day timer service for natural disasters
    stopService(new Intent(runGraphics.this, NaturalDisaster.class));

    meteorAndStormStatus = new BroadcastReceiver()
    {
        @Override
        public void onReceive(Context context, Intent intent) 
        {
            meteorExists = intent.getBooleanExtra("meteorStat", false);
            Toast.makeText(getApplicationContext(), "Here we are: " + meteorExists, Toast.LENGTH_SHORT).show();
            if (meteorExists == true)
            {
                //on click listener for meteor
                meteor = (ImageButton) findViewById(R.id.meteor);
                meteor.setVisibility(View.VISIBLE);
                meteor.setOnClickListener(new OnClickListener()
                {

                    @Override
                    public void onClick(View v) 
                    {
                        if (wasMined == false)
                        {
                            meteorRockAmount += 50;
                            wasMined = true;
                        }//end if
                    }//end onClick function

                });//end setOnClickListener
            }//end if
        }//end onReceive function
    };//end meteorAndStormStatus BroadcastReceiver
    LocalBroadcastManager.getInstance(getApplicationContext()).registerReceiver(meteorAndStormStatus, new IntentFilter("meteorStat"));

here is the code sending the broadcast

        //send broadcast back that a meteor exists
        Intent i = new Intent();
        i.putExtra("meteorStat", true);
        LocalBroadcastManager.getInstance(getApplicationContext()).sendBroadcast(i);

Here is my logcat:

06-06 23:30:22.318: E/AndroidRuntime(21714): FATAL EXCEPTION: main
06-06 23:30:22.318: E/AndroidRuntime(21714): java.lang.NullPointerException
06-06 23:30:22.318: E/AndroidRuntime(21714):    at com.project.llb.runGraphics$1.onReceive(runGraphics.java:113)
06-06 23:30:22.318: E/AndroidRuntime(21714):    at android.support.v4.content.LocalBroadcastManager.executePendingBroadcasts(LocalBroadcastManager.java:297)
06-06 23:30:22.318: E/AndroidRuntime(21714):    at android.support.v4.content.LocalBroadcastManager.access$000(LocalBroadcastManager.java:46)
06-06 23:30:22.318: E/AndroidRuntime(21714):    at android.support.v4.content.LocalBroadcastManager$1.handleMessage(LocalBroadcastManager.java:116)
06-06 23:30:22.318: E/AndroidRuntime(21714):    at android.os.Handler.dispatchMessage(Handler.java:99)
06-06 23:30:22.318: E/AndroidRuntime(21714):    at android.os.Looper.loop(Looper.java:130)
06-06 23:30:22.318: E/AndroidRuntime(21714):    at android.app.ActivityThread.main(ActivityThread.java:3806)
06-06 23:30:22.318: E/AndroidRuntime(21714):    at java.lang.reflect.Method.invokeNative(Native Method)
06-06 23:30:22.318: E/AndroidRuntime(21714):    at java.lang.reflect.Method.invoke(Method.java:507)
06-06 23:30:22.318: E/AndroidRuntime(21714):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
06-06 23:30:22.318: E/AndroidRuntime(21714):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
06-06 23:30:22.318: E/AndroidRuntime(21714):    at dalvik.system.NativeStart.main(Native Method)

Also, I do unregister the receiver in my onPause() of the class with the onReceive. Any help would be appreciated. Thanks in advance.

Answer 1

The problem was that I had an if statement if(meteorExists == false) and inside this statement I had meteor.setVisibility(View.INVISIBLE). The problem is that this will give a NullPointerException if the original if is not visited first. So to fix the issue, I had to include a meteor = (ImageButton) findViewById(R.id.meteor); before I tried to set the meteor to invisible. Thanks for the help guys. You pointed me in the right direction.