StackOverflowError, anyone know how to fix?

Now I am getting this error:

Code:

[00:37:06 ERROR]: Could not pass event BlockBreakEvent to Levels v0.1
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:294) ~[bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at net.minecraft.server.v1_7_R3.PlayerInteractManager.breakBlock(PlayerInteractManager.java:263) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at net.minecraft.server.v1_7_R3.PlayerInteractManager.a(PlayerInteractManager.java:191) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at net.minecraft.server.v1_7_R3.PlayerConnection.a(PlayerConnection.java:549) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at net.minecraft.server.v1_7_R3.PacketPlayInBlockDig.a(SourceFile:53) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at net.minecraft.server.v1_7_R3.PacketPlayInBlockDig.handle(SourceFile:8) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at net.minecraft.server.v1_7_R3.NetworkManager.a(NetworkManager.java:157) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at net.minecraft.server.v1_7_R3.ServerConnection.c(SourceFile:134) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.v(MinecraftServer.java:667) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at net.minecraft.server.v1_7_R3.DedicatedServer.v(DedicatedServer.java:260) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.u(MinecraftServer.java:558) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:469) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:628) [bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
Caused by: java.lang.NullPointerException
    at Skills.Mining.onBlockBreak(Mining.java:25) ~[?:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_05]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_05]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_05]
    at java.lang.reflect.Method.invoke(Method.java:483) ~[?:1.8.0_05]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) ~[bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    ... 15 more

Levels.class(Main Class)

Code:java

package Kassestral.Levels;
 
import java.io.File;
 
import org.bukkit.Bukkit;
import org.bukkit.plugin.PluginManager;
import org.bukkit.plugin.java.JavaPlugin;
 
import Skills.Mining;
import Skills.Smithing;
 
public class Levels extends JavaPlugin
{
    PluginManager pm = Bukkit.getServer().getPluginManager();;
    public void onEnable()
    {
        CreateDirectories();
        pm.registerEvents(new API(), this);
        pm.registerEvents(new Handlers(), this);
        pm.registerEvents(new Smithing(), this);
        pm.registerEvents(new Mining(), this);
    }
 
    public void onDisable()
    {
 
    }
 
    private void CreateDirectories()
    {
        // Creates Main Directory
        File MainDir = new File(getDataFolder() + "/");
        if(!MainDir.exists())
        {
            MainDir.mkdir();
        }
        // Creates Main Directory
 
        // Creates Players Directory
        File PlayersDir = new File(getDataFolder() + "/" + File.separator + "players");
        if(!PlayersDir.exists())
        {
            PlayersDir.mkdir();
            getLogger().info("Folders Created");
        }
        // Creates Players Directory
    }
 
 
}

Handlers.class

Code:java

package Kassestral.Levels;
 
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerJoinEvent;
 
public class Handlers implements Listener
{
    API api;
    public API getAPI(){
        return api;
    }
 
    //Handlers Begin
    @EventHandler
    public void onPlayerJoin(PlayerJoinEvent e)
    {
        Player p = e.getPlayer();
        api.CreatePlayerFile(p);
    }
}

API.class

Code:java

package Kassestral.Levels;
 
import java.io.File;
import java.io.IOException;
 
import org.bukkit.configuration.file.FileConfiguration;
import org.bukkit.configuration.file.YamlConfiguration;
import org.bukkit.entity.Player;
import org.bukkit.event.Listener;
 
public class API implements Listener
{
    FileConfiguration PlayerConfig;
    File PlayerFile;
    Player player;
 
 
 
    Levels levels;
    public Levels getlevel(){
        return getLevels();
    }
 
    //Methods Start
    public void LPlayer(Player p)
    {
        this.player = p;
        this.PlayerFile = new File(getLevels().getDataFolder() + "/" + File.separator + "players" + File.separator + p.getUniqueId().toString() + ".yml");
        this.PlayerConfig = YamlConfiguration.loadConfiguration(this.PlayerFile);
    }
 
    public Player getPlayer() {
        return this.player;
      }
 
    public String getName() {
        return this.player.getName();
      }
 
    public File getUserFile() {
        return this.PlayerFile;
      }
 
    public FileConfiguration getUserConfig() {
        return this.PlayerConfig;
      }
 
    public void save()
    {
            try {
              this.PlayerConfig.save(this.PlayerFile);
            } catch (IOException e) {
              e.printStackTrace();
            }
          }
 
    public void CreatePlayerFile(Player p)
    {
    this.PlayerFile = new File(getLevels().getDataFolder() + "/" + File.separator + "players" + File.separator + p.getUniqueId().toString() + ".yml");
    this.PlayerConfig = YamlConfiguration.loadConfiguration(this.PlayerFile);
 
      if(!PlayerFile.exists()){
        try{
      PlayerFile.createNewFile();
      PlayerConfig = YamlConfiguration.loadConfiguration(PlayerFile);
      PlayerConfig.createSection("Levels.Farming");
      PlayerConfig.set("Levels.Farming", 0);
      PlayerConfig.createSection("Levels.Mining");
      PlayerConfig.set("Levels.Mining", 0);
      PlayerConfig.createSection("Levels.Smithing");
      PlayerConfig.set("Levels.Smithing", 0);
      PlayerConfig.createSection("Levels.Hunting");
      PlayerConfig.set("Levels.Hunting", 0);
      PlayerConfig.createSection("Levels.Cooking");
      PlayerConfig.set("Levels.Cooking", 0);
      PlayerConfig.createSection("Levels.Combat");
      PlayerConfig.set("Levels.Combat", 0);
      PlayerConfig.createSection("Levels.Archery");
      PlayerConfig.set("Levels.Archery", 0);
      PlayerConfig.save(PlayerFile);
            }
      catch (IOException e){
      e.printStackTrace();
        }
        }
      }
 
    public int getXP(String level)
    {
        return this.PlayerConfig.getInt(level);
    }
 
    public void setXP(String s, int i)
    {
        getUserConfig().set(s, Integer.valueOf(i));
        save();
    }
 
    public void addExp(String s, int i)
    {
        int before = getXP(s);
        before += i;
        setXP(s, before);
    }
 
    //Methods End
 
    public Kassestral.Levels.Levels getLevels() {
        return levels;
    }
}

Mining.class

Code:java

package Skills;
 
import org.bukkit.Material;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.block.BlockBreakEvent;
 
import Kassestral.Levels.API;
 
public class Mining implements Listener
{
    API api;
    public API getAPI(){
        return api;
    }
 
    @EventHandler
    public void onBlockBreak(BlockBreakEvent e)
    {
        Material Block = e.getBlock().getType();
        String s = "Levels.Mining";
 
        if(Block == Material.STONE)
        {
            api.addExp(s, 5);
        }
        if(Block == Material.COAL_ORE)
        {
            api.addExp(s, 20);
        }
        if(Block == Material.LAPIS_ORE)
        {
            api.addExp(s, 20);
        }
        if(Block == Material.IRON_ORE)
        {
            api.addExp(s, 25);
        }
        if(Block == Material.GOLD_ORE)
        {
            api.addExp(s, 50);
        }
        if(Block == Material.DIAMOND_ORE)
        {
            api.addExp(s, 100);
        }
        if(Block == Material.EMERALD_ORE)
        {
            api.addExp(s, 250);
        }
    }
}

Smithing.class

Code:java

package Skills;
 
import org.bukkit.Material;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.event.inventory.InventoryType.SlotType;
import org.bukkit.inventory.ItemStack;
 
import Kassestral.Levels.API;
 
public class Smithing implements Listener
{
    API api;
    public API getAPI(){
        return api;
    }
 
    @EventHandler
    public void onItemCraft(InventoryClickEvent e)
    {
        if(e.getSlotType() == SlotType.RESULT)
        {
            String S = "Levels.Smithing";
 
            ItemStack l_helm = new ItemStack(Material.LEATHER_HELMET);
            ItemStack l_chest = new ItemStack(Material.LEATHER_CHESTPLATE);
            ItemStack l_legs = new ItemStack(Material.LEATHER_LEGGINGS);
            ItemStack l_boots = new ItemStack(Material.LEATHER_BOOTS);
 
            ItemStack i_helm = new ItemStack(Material.IRON_HELMET);
            ItemStack i_chest = new ItemStack(Material.IRON_CHESTPLATE);
            ItemStack i_legs = new ItemStack(Material.IRON_LEGGINGS);
            ItemStack i_boots = new ItemStack(Material.IRON_BOOTS);
            ItemStack i_sword = new ItemStack(Material.IRON_SWORD);
 
            ItemStack d_helm = new ItemStack(Material.DIAMOND_HELMET);
            ItemStack d_chest = new ItemStack(Material.DIAMOND_CHESTPLATE);
            ItemStack d_legs = new ItemStack(Material.DIAMOND_LEGGINGS);
            ItemStack d_boots = new ItemStack(Material.DIAMOND_BOOTS);
            ItemStack d_sword = new ItemStack(Material.DIAMOND_SWORD);
 
 
            //Leather Recipes
            if(e.getResult().equals(l_helm))
            {
                api.addExp(S, 50);
            }
            if(e.getResult().equals(l_chest))
            {
                api.addExp(S, 80);
            }
            if(e.getResult().equals(l_legs))
            {
                api.addExp(S, 70);
            }
            if(e.getResult().equals(l_boots))
            {
                api.addExp(S, 40);
            }
            //Leather Recipes End
 
            //Iron Recipes
            if(e.getResult().equals(i_helm))
            {
                api.addExp(S, 125);
            }
            if(e.getResult().equals(i_chest))
            {
                api.addExp(S, 200);
            }
            if(e.getResult().equals(i_legs))
            {
                api.addExp(S, 175);
            }
            if(e.getResult().equals(i_boots))
            {
                api.addExp(S, 100);
            }
            if(e.getResult().equals(i_sword))
            {
                api.addExp(S, 50);
            }
            //Iron End
 
            //Diamond Recipes
            if(e.getResult().equals(d_helm))
            {
                api.addExp(S, 500);
            }
            if(e.getResult().equals(d_chest))
            {
                api.addExp(S, 800);
            }
            if(e.getResult().equals(d_legs))
            {
                api.addExp(S, 700);
            }
            if(e.getResult().equals(d_boots))
            {
                api.addExp(S, 400);
            }
            if(e.getResult().equals(d_sword))
            {
                api.addExp(S, 200);
            }
            //Diamond Recipes End
        }
 
 
    }
 
    public void onSmelt(InventoryClickEvent e)
    {
        String S = "Levels.Smithing";
        ItemStack i = new ItemStack(Material.IRON_INGOT);
        ItemStack g = new ItemStack(Material.GOLD_INGOT);
        ItemStack d = new ItemStack(Material.DIAMOND);
        ItemStack em = new ItemStack(Material.EMERALD);
 
        if(e.getResult().equals(i))
        {
            api.addExp(S, 20);
        }
        if(e.getResult().equals(g))
        {
            api.addExp(S, 50);
        }
        if(e.getResult().equals(d))
        {
            api.addExp(S, 100);
        }
        if(e.getResult().equals(em))
        {
            api.addExp(S, 250);
        }
 
    }
 
}

 

You created a infinite loop of "new" objects

 

can you show me how to fix it?

 

Kassestral
It will keep looping through these two pieces of code

Code:java

public Mining(Plugin levels) // 4. gets called by the API class
{
    this.Levels = levels;
    this.api = new API(levels); // 1. calls the API
}

Code:java

public API(Plugin levels) // 2. gets called by the Mining class
{
    this.Levels = levels;
    this.mining = new Skills.Mining(levels); // 3. calls the Mining class
    this.smithing = new Skills.Smithing(levels);
}

 

Could use a singleton.

 

Well, you just need to see what MrSparkzz said and try to close the loop (by keeping instances of your classes instead of creating "new" things everytime)

 

I fixed it now, but now when I break a stone block it springs

Code:

Caused by: java.lang.NullPointerException
    at Skills.Mining.onBlockBreak(Mining.java:30) ~[?:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_05]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_05]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_05]
    at java.lang.reflect.Method.invoke(Method.java:483) ~[?:1.8.0_05]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) ~[bukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
    ... 15 more

ZeusAllMighty11 rfsantos1996

 

Keep all the instances in your main class and access them from the external classes.

Also, it's nice to see that all your variables/methods are readable.

Your packages, however, seem a bit odd. I'd recommend checking out the Java documentation on packages.

 

Can you send us the line 30 of the file Mining.java? (also, there is a thread somewhere about how to read stack trace, it is VERY useful (; )

 

rfsantos1996
30: api.addExp(s, 5);

 

Maybe API is null... I don't see any other cause besides that, the addExp/setExp don't seem able to throw any error

 

API is null because you never actually set it, which he doesn't know because you never posted the code here.

 

Garris0n rfsantos1996 rfsantos1996
Check the top post again I updated it with classes + current error

 

Kassestral
Change

Code:java

API api;
public API getAPI(){
    return api;
}

to

Code:java

API api = API.getAPI();

 

I said to create instance variables for all of the classes and put them in the main class along with a getter for each one.

What you did was to put instance variables of the API class into every other class along with a getter.

Telling him to use static singletons probably isn't the best idea.

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

 

Garris0n MrSparkzz
So what exaclty am I doing?

 

Garris0n
I don't see why not. It works, and if he runs into an error, there can be a fix. And I don't know why you wouldn't use the way I said. Why do you say that it isn't the best idea?

Kassestral
Do what I said, if you run into more problems, let me or someone else know, unless you can solve the problem on your own.

 

Because he barely seems to understand how the instances work in the first place and using static singletons is pretty much guaranteed to throw that understanding off more.

@OP, I'm just gonna leave this here and hope you read it, preferably before doing anything else.
http://docs.oracle.com/javase/tutorial/java/javaOO/classvars.html

The entire section would probably be helpful, really.
http://docs.oracle.com/javase/tutorial/java/javaOO/index.html

 

I read it and I understand it allot more now then before

 

Kassestral
If your issue is resolved, please set this thread to solved.

 

If anything I have made it worse, my onPlayerJoinEvent now has a null exception aswelll...

 

Kassestral
Show the new code of the class which contains the onPlayerJoinEvent and the console errors (stacktrace)