Shared Preferences crashes program

Question

Im trying to make this thing that generates worlds in my application for android but the ListActivity never opens because of the shared preferences. It says there is a storage null pointer exception, but I can't find a way to fix that. Any ideas? (It worked perfectly fine without the shared preferences.)

Code:

       

1. //List Activity
   import android.app.ListActivity;
   import android.content.Intent;
   import android.content.SharedPreferences;
   import android.content.SharedPreferences.Editor;
   import android.os.Bundle;
   import android.view.View;
   import android.widget.ArrayAdapter;
   import android.widget.ListView;
    
   public class WorldMenu extends ListActivity{
   String worldString2;
   String worldString;
   static String worldString3;
   String[] worldMenu;
       SharedPreferences worldList;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
   // TODO Auto-generated method stub
   super.onCreate(savedInstanceState);
   setListAdapter(new ArrayAdapter<String>(WorldMenu.this, android.R.layout.simple_list_item_1, worldMenu));
   worldMenu = worldString3.split(",");
   worldMenu[worldMenu.length] = "Create World";
   worldString = "Create World,";
   worldList = getSharedPreferences("worldString",0);
   worldString3 = worldList.getString("worldString", "Worlds not found.");
   }
    
   @Override
   protected void onPause() {
   // TODO Auto-generated method stub
   super.onPause();
   worldString2 = worldString3;
   Editor editor = worldList.edit();
   editor.putString("worldStuff",worldString2);
   editor.commit();
   }
    
   @Override
   protected void onListItemClick(ListView l, View v, int position, long id) {
   // TODO Auto-generated method stub
   super.onListItemClick(l, v, position, id);
    
   if(position == 0){
   Intent openGenerator = new Intent("blablabla.WORLDNAME");
   startActivity(openGenerator);
   }
   }
    
    
   }
2. package x.x.x;

    

   //Naming Activity

   import android.app.Activity;

   import android.content.Intent;

   import android.content.SharedPreferences;

   import android.content.SharedPreferences.Editor;

   import android.os.Bundle;

   import android.view.View;

   import android.widget.Button;

   import android.widget.EditText;

    

   public class worldName extends Activity{

   EditText worldType;

   String worldName; 

   Button save;

   SharedPreferences wname;

   String nameworld = "worldName";

   @Override

   protected void onCreate(Bundle savedInstanceState) {

   // TODO Auto-generated method stub

   super.onCreate(savedInstanceState);

   setContentView(R.layout.activity_worldname);

   wname = getSharedPreferences("worldName",0);

   worldType = (EditText) findViewById(R.id.editText1);

   save = (Button) findViewById(R.id.button1);

   save.setOnClickListener(new View.OnClickListener() {

    

   @Override

   public void onClick(View v) {

   // TODO Auto-generated method stub

   worldName = worldType.getText().toString();

   WorldMenu.worldString3 += worldName+",";

   Intent intent = new Intent("com.mtprogramming.blockfight.WORLDGENERATOR");

   startActivity(intent);

   }

   });

   }

    

   }