Optimized for Error, OutOfMemoryError:

Hello,
I have a little memory problem when I perform my function.

Code:

package fr.passepartout007.gestionterrain;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.util.HashMap;
import java.util.concurrent.TimeUnit;

import org.bukkit.Location;
import org.bukkit.World;
import org.bukkit.block.data.BlockData;
import org.bukkit.entity.Player;

import fr.passepartout007.gestionbasedonnee.basededonne;
import fr.passepartout007.lancementplugin.lancement;
public class SaveNewArena extends Arena{

    public SaveNewArena(lancement lancement) {
        super(lancement);
        // TODO Auto-generated constructor stub
    }
   
    public void exportNewArena(Player player, String name) {
        World world = player.getWorld();
        player.sendMessage("§bSauvegarde de la map");
        HashMap<String,BlockData> saveBlock = new HashMap<String,BlockData>();
        //boucleZ
        for(int i= -1232 ; i<-1098 ; i++) {
            //bouclex
            for(int j= -1285 ; j <-1179 ; j++) {
                for(int k=0 ; k<69 ;k++) {
                    Location location = new Location(world, i, k, j);
                   
                        BlockData data = location.getBlock().getBlockData();
                        saveBlock.put(location.toString(),data);
                   
                }

            }
            try {
                TimeUnit.MILLISECONDS.sleep(500);
           
                player.sendMessage("§bIl reste : §f" + (((i*-1)-1098) + " couches"));
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        basededonne bdd = new basededonne();
        String chemin = name +"txt";
        chemin = bdd.CheminFichier(chemin);
       
        exportArenaData(chemin,saveBlock);
    }
   
    public void exportArenaData(String chemin,HashMap<String,BlockData> saveBlock ) {
        ObjectOutputStream oos;
        try {
           
            oos = new ObjectOutputStream(
                      new BufferedOutputStream(
                              new FileOutputStream(
                                new File(chemin))));
           
            oos.writeObject(saveBlock);
            oos.close();
       
        } catch (FileNotFoundException e) {
              e.printStackTrace();
        } catch (IOException e) {
          e.printStackTrace();
        }  
    }
}

Here is the error:

Code:

org.bukkit.event.EventException: null
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:320) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:529) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:514) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at org.bukkit.craftbukkit.v1_15_R1.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:437) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.PlayerInteractManager.a(PlayerInteractManager.java:441) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.PlayerConnection.a(PlayerConnection.java:1250) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.PacketPlayInUseItem.a(PacketPlayInUseItem.java:27) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.PacketPlayInUseItem.a(PacketPlayInUseItem.java:1) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:19) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.TickTask.run(SourceFile:18) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeTask(SourceFile:144) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeNext(SourceFile:118) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.MinecraftServer.aZ(MinecraftServer.java:917) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.MinecraftServer.executeNext(MinecraftServer.java:910) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.awaitTasks(SourceFile:127) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.MinecraftServer.sleepForTick(MinecraftServer.java:894) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:827) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_251]
Caused by: java.lang.OutOfMemoryError: GC overhead limit exceeded
        at java.util.Arrays.copyOf(Unknown Source) ~[?:1.8.0_251]
        at java.lang.AbstractStringBuilder.ensureCapacityInternal(Unknown Source) ~[?:1.8.0_251]
        at java.lang.AbstractStringBuilder.append(Unknown Source) ~[?:1.8.0_251]
        at java.lang.StringBuilder.append(Unknown Source) ~[?:1.8.0_251]
        at java.lang.StringBuilder.append(Unknown Source) ~[?:1.8.0_251]
        at org.bukkit.Location.toString(Location.java:586) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at fr.passepartout007.gestionterrain.SaveNewArena.exportNewArena(SaveNewArena.java:40) ~[?:?]
        at fr.passepartout007.phasedujeux.attenteduJeux.onInteract(attenteduJeux.java:78) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_251]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_251]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_251]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_251]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:316) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:529) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:514) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at org.bukkit.craftbukkit.v1_15_R1.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:437) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.PlayerInteractManager.a(PlayerInteractManager.java:441) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.PlayerConnection.a(PlayerConnection.java:1250) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.PacketPlayInUseItem.a(PacketPlayInUseItem.java:27) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.PacketPlayInUseItem.a(PacketPlayInUseItem.java:1) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:19) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.PlayerConnectionUtils$$Lambda$3475/1770178518.run(Unknown Source) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.TickTask.run(SourceFile:18) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeTask(SourceFile:144) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeNext(SourceFile:118) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.MinecraftServer.aZ(MinecraftServer.java:917) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.MinecraftServer.executeNext(MinecraftServer.java:910) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.awaitTasks(SourceFile:127) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.MinecraftServer.sleepForTick(MinecraftServer.java:894) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:827) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
[17:33:51] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 61069ms or 1221 ticks behind
[17:33:51] [Server thread/WARN]: passepartout007 moved too quickly! -9.231519595640066,4.5,-1.1644467944779535

I don't understand why this code takes so much memory ... can you help me optimize my code to avoid this error?
faithfully,
Passepartout007

 

1232 - 1098 = 134
1285 - 1179 = 106
134 * 106 * 69 = 980,076

You are creating close to a million Location and BlockData objects in that nested loop of yours.
That'll do it every time