NullPointer with List

This is the first time I have used a list inside of a config file. I assume that I am doing most of this correctly, however I get a NullPointerException from the line:

Code:

worldList.add("world");

I am trying to create a Hardcore Minecraft plugin, but cannot get the worlds to be added to a list properly.

Here is the error:

Code:

[23:09:22 ERROR]: Error occurred while enabling Hardcore v1 (Is it up to date?)
java.lang.NullPointerException
        at com.trig.hardcore.Hardcore.onEnable(Hardcore.java:41) ~[?:?]
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217) ~[c
raftbukkit.jar:git-Bukkit-1.6.4-R2.0-37-g4857595-b2951jnks]
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader
.java:457) [craftbukkit.jar:git-Bukkit-1.6.4-R2.0-37-g4857595-b2951jnks]
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManage
r.java:381) [craftbukkit.jar:git-Bukkit-1.6.4-R2.0-37-g4857595-b2951jnks]
        at org.bukkit.craftbukkit.v1_7_R1.CraftServer.loadPlugin(CraftServer.jav
a:298) [craftbukkit.jar:git-Bukkit-1.6.4-R2.0-37-g4857595-b2951jnks]
        at org.bukkit.craftbukkit.v1_7_R1.CraftServer.enablePlugins(CraftServer.
java:280) [craftbukkit.jar:git-Bukkit-1.6.4-R2.0-37-g4857595-b2951jnks]
        at net.minecraft.server.v1_7_R1.MinecraftServer.m(MinecraftServer.java:3
38) [craftbukkit.jar:git-Bukkit-1.6.4-R2.0-37-g4857595-b2951jnks]
        at net.minecraft.server.v1_7_R1.MinecraftServer.g(MinecraftServer.java:3
15) [craftbukkit.jar:git-Bukkit-1.6.4-R2.0-37-g4857595-b2951jnks]
        at net.minecraft.server.v1_7_R1.MinecraftServer.a(MinecraftServer.java:2
75) [craftbukkit.jar:git-Bukkit-1.6.4-R2.0-37-g4857595-b2951jnks]
        at net.minecraft.server.v1_7_R1.DedicatedServer.init(DedicatedServer.jav
a:175) [craftbukkit.jar:git-Bukkit-1.6.4-R2.0-37-g4857595-b2951jnks]
        at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java
:420) [craftbukkit.jar:git-Bukkit-1.6.4-R2.0-37-g4857595-b2951jnks]
        at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:6
17) [craftbukkit.jar:git-Bukkit-1.6.4-R2.0-37-g4857595-b2951jnks]

Here is my code:

Code:

public class Hardcore extends JavaPlugin implements Listener {
 
    public int startingLives;
    public List<String> worldList;
 
    public void onEnable() {
        if(!getDataFolder().exists()) {
            saveConfig();
            getConfig().createSection("general");
            getConfig().createSection("general.firstSetup");
            getConfig().createSection("general.playerLives");
            getConfig().createSection("general.overrideDifficulty");
            getConfig().createSection("general.world");
            getConfig().createSection("general.forceNumberOfMobs");
            getConfig().createSection("general.maxMobs");
            getConfig().createSection("general.pvp");
            getConfig().set("general.firstSetup", false);
            getConfig().set("general.playerLives", 2);
            getConfig().set("general.overrideDifficulty", true);
            getConfig().set("general.forceNumberOfMobs", true);
            getConfig().set("general.maxMobs", 100);
            getConfig().set("general.pvp", true);
            getConfig().createSection("general.worlds");
            worldList = (List<String>)getConfig().getList("general.worlds");
            worldList.add("world");
            getConfig().set("general.worlds", worldList);
        }
        worldList = (List<String>)getConfig().getList("general.worlds");
        saveConfig();
        if(getConfig().getBoolean("general.firstSetup") == false) { //This section probably isn't needed, but whatever.
            startingLives = getConfig().getInt("general.playerLives");
            getConfig().set("general.firstSetup", true);
        }
     
        if(getConfig().getBoolean("general.overrideDiffiulty") == true) {
            for(int i = 0; i < worldList.size(); i++) {
                Bukkit.getServer().getWorld(worldList.get(i)).setDifficulty(Difficulty.HARD);
            }
        }
        if(getConfig().getBoolean("general.forceNumberOfMobs") == true) {
            for(int i = 0; i < worldList.size(); i++) {
                Bukkit.getServer().getWorld(worldList.get(i)).setAnimalSpawnLimit(getConfig().getInt("general.maxMobs"));
            }
        }
        if(getConfig().getBoolean("general.pvp") == true) {
            for(int i = 0; i < worldList.size(); i++) {
                Bukkit.getServer().getWorld(worldList.get(i)).setPVP(true);
            }
        }
        Bukkit.getServer().getPluginManager().registerEvents(this, this);
        try {
            getConfig().load(getDataFolder().getAbsolutePath() + "/config.yml");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

Now I understand I can change a few things in my code, like just make things CopyFromDefault, but I would like to see how to solve this issue...

 

Actually you should be looking at the line:

Code:java

worldList = (List<String>)getConfig().getList("general.worlds");

Since that's what's making worldList null. When you get the list, wouldn't there not be any worlds?

 

Changed it to

Code:java

saveConfig();
            getConfig().createSection("general");
            getConfig().createSection("general.firstSetup");
            getConfig().createSection("general.playerLives");
            getConfig().createSection("general.overrideDifficulty");
            getConfig().createSection("general.world");
            getConfig().createSection("general.forceNumberOfMobs");
            getConfig().createSection("general.maxMobs");
            getConfig().createSection("general.pvp");
            getConfig().set("general.firstSetup", false);
            getConfig().set("general.playerLives", 2);
            getConfig().set("general.overrideDifficulty", true);
            getConfig().set("general.forceNumberOfMobs", true);
            getConfig().set("general.maxMobs", 100);
            getConfig().set("general.pvp", true);
            getConfig().createSection("general.worlds");
            getConfig().set("general.worlds", "world");
            worldList = (List<String>)getConfig().getList("general.worlds");
            worldList.add("world");
            getConfig().set("general.worlds", worldList);

And it's still null :/
Any other suggestions?

I'd like to get this fixed ASAP, so any help would be fantastic

Bump...

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Use getConfig().getStringList(); to get the list. This will never return null, not to mention remove the dangerous cast.

 

Now this part returns null...

Code:java

if(getConfig().getBoolean("general.forceNumberOfMobs") == true) {
            for(int i = 0; i < worldList.size(); i++) {
                Bukkit.getServer().getWorld(worldList.get(i)).setMonsterSpawnLimit(getConfig().getInt("general.maxMobs"));
            }
        }

The line that returns the error is

Code:java

Bukkit.getServer().getWorld(worldList.get(i)).setMonsterSpawnLimit(getConfig().getInt("general.maxMobs"));

**SOLVED**
Just used different for loops...

Code:java

for(String s : worldList) {

-------Changes since first post-------------
(Incase somebody uses this in the future)

Code:java

List<String> worldList = (List<String>)getConfig().getList("general.worlds");
//Changed to
worldList = (List<String>)getConfig().getStringList("general.worlds");
 
//For loops changed to
for(String s : worldList) {
}
 

EDIT by Moderator: merged posts, please use the edit button instead of double posting.