How to make a ArrayList of block position on the server side and save it so it can be loaded the next time the server reopens?

I'm starting to understand how WorldSavedData works, but when reload the game it doesn't load any data. Help?

 

package com.cbultimate.stranded;

import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.nbt.NBTTagList;
import net.minecraft.world.WorldSavedData;
import java.util.ArrayList;

//Created by CBU on 17/1/2017.

public class ModWorldSavedData extends WorldSavedData {
    public static ArrayList<Vector3> ToolCupboards = new ArrayList<Vector3>();

    public ModWorldSavedData(String name) {
        super(name);
    }

    @Override
    public void readFromNBT(NBTTagCompound nbt) {
        NBTTagList cupboardList = nbt.getTagList("ToolCupboards", 10);
        ToolCupboards.clear();
        for (int i=0; i< cupboardList.tagCount(); i++){
            NBTTagCompound newCompound = cupboardList.getCompoundTagAt(i);
            int X = newCompound.getInteger("x");
            int Y = newCompound.getInteger("y");
            int Z = newCompound.getInteger("z");
            ToolCupboards.add(new Vector3(X, Y, Z));
        }
        System.out.println("Loaded " + ToolCupboards.size() + " cupboards.");
    }

    @Override
    public NBTTagCompound writeToNBT(NBTTagCompound compound) {
        NBTTagList cupboardList = new NBTTagList();
        for (int i=0;i<ToolCupboards.size(); i++){
            NBTTagCompound newCompound = new NBTTagCompound();
            Vector3 position = ToolCupboards.get(i);
            newCompound.setInteger("x", position.x);
            newCompound.setInteger("y", position.y);
            newCompound.setInteger("z", position.z);
            cupboardList.appendTag(newCompound);
        }
        compound.setTag("ToolCupboards", cupboardList);
        return compound;
    }
}

 

    private final static String cupboard_dataIdentifier = "ToolCupboards";

    @SubscribeEvent
    public void blockPlacedEvent(BlockEvent.PlaceEvent event){
        System.out.println("(" + event.getPlacedBlock().getBlock().getUnlocalizedName() + ") was placed " + event.getPos().toString());
        World world = event.getWorld();
        ModWorldSavedData modWorldSavedData = (ModWorldSavedData) world.getPerWorldStorage().getOrLoadData(ModWorldSavedData.class, cupboard_dataIdentifier);

        if (modWorldSavedData == null) {
            modWorldSavedData = new ModWorldSavedData(cupboard_dataIdentifier);
        }

        if (event.getPlacedBlock().getBlock().getUnlocalizedName().equals("tile.wooden_toolcupboard")){
            ModWorldSavedData.ToolCupboards.add(new Vector3(event.getPos().getX(), event.getPos().getY(), event.getPos().getZ()));
        }

        world.getPerWorldStorage().setData(cupboard_dataIdentifier, modWorldSavedData);
        System.out.println("Tool Cupboards: " + ModWorldSavedData.ToolCupboards.size());
    }

Sorry, but I got it working. I just had to markDirty(). It works perfectly now. I'm just making this for my learning so com.cbultimate is just my name and .com. Domain name's not taken. Thanks for your help.

 

package com.cbultimate.stranded;

import net.minecraft.world.World;
import net.minecraftforge.event.world.BlockEvent;
import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
import net.minecraftforge.fml.common.gameevent.PlayerEvent;

//Created by CBU on 14/1/2017.

public class ModEventHandler {

    @SubscribeEvent
    public void playerLoggedInEvent(PlayerEvent.PlayerLoggedInEvent event){
        System.out.println(event.player.getDisplayName() + " has logged in the server.");
    }

    private final static String cupboard_dataIdentifier = "ToolCupboards";

    @SubscribeEvent
    public void blockPlacedEvent(BlockEvent.PlaceEvent event){
        System.out.println("(" + event.getPlacedBlock().getBlock().getUnlocalizedName() + ") was placed " + event.getPos().toString());
        World world = event.getWorld();
        ModWorldSavedData modWorldSavedData = (ModWorldSavedData) world.getPerWorldStorage().getOrLoadData(ModWorldSavedData.class, cupboard_dataIdentifier);

        if (modWorldSavedData == null) {
            modWorldSavedData = new ModWorldSavedData(cupboard_dataIdentifier);
        }

        if (event.getPlacedBlock().getBlock().getUnlocalizedName().equals("tile.wooden_toolcupboard")){
            ModWorldSavedData.ToolCupboards.add(new Vector3(event.getPos().getX(), event.getPos().getY(), event.getPos().getZ()));
            world.getPerWorldStorage().setData(cupboard_dataIdentifier, modWorldSavedData);
            modWorldSavedData.markDirty();
            System.out.println("Tool Cupboards: " + ModWorldSavedData.ToolCupboards.size());
        }
    }
}

 

package com.cbultimate.stranded;

import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.nbt.NBTTagList;
import net.minecraft.world.WorldSavedData;
import java.util.ArrayList;

//Created by CBU on 17/1/2017.

public class ModWorldSavedData extends WorldSavedData {
    public static ArrayList<Vector3> ToolCupboards = new ArrayList<Vector3>();

    public ModWorldSavedData(String name) {
        super(name);
    }

    @Override
    public void readFromNBT(NBTTagCompound nbt) {
        NBTTagList cupboardList = nbt.getTagList("ToolCupboards", 10);
        ToolCupboards.clear();
        for (int i=0; i< cupboardList.tagCount(); i++){
            NBTTagCompound newCompound = cupboardList.getCompoundTagAt(i);
            int X = newCompound.getInteger("x");
            int Y = newCompound.getInteger("y");
            int Z = newCompound.getInteger("z");
            ToolCupboards.add(new Vector3(X, Y, Z));
        }
        System.out.println("Loaded " + ToolCupboards.size() + " cupboards.");
    }

    @Override
    public NBTTagCompound writeToNBT(NBTTagCompound compound) {
        NBTTagList cupboardList = new NBTTagList();
        for (int i=0;i<ToolCupboards.size(); i++){
            NBTTagCompound newCompound = new NBTTagCompound();
            Vector3 position = ToolCupboards.get(i);
            newCompound.setInteger("x", position.x);
            newCompound.setInteger("y", position.y);
            newCompound.setInteger("z", position.z);
            cupboardList.appendTag(newCompound);
        }
        compound.setTag("ToolCupboards", cupboardList);
        return compound;
    }
}

 

I'm sorry if this may sound stupid but If I remove static, my ModEventHandler class can't access it. From there on I'm not sure what to do. I've renamed my mod to mod.cbultimate. Thanks for the tip, my unlocalized names includes ModID now. Thanks for that too.