http://www.bukkit.fr/topic/19012-probl%C3%A8me-avec-le-syst%C3%A8me-de-cuboide-de-vinetos/

Plugin.java

package fr.neatmonster.plugin;

import java.util.HashMap;
import java.util.Map;

import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.World;
import org.bukkit.configuration.serialization.ConfigurationSerializable;
import org.bukkit.configuration.serialization.ConfigurationSerialization;
import org.bukkit.configuration.serialization.SerializableAs;
import org.bukkit.plugin.java.JavaPlugin;

import fr.neatmonster.plugin.Plugin.SSelection.SLocation;

public class Plugin extends JavaPlugin {
    @SerializableAs("Selection")
    public static class SSelection implements ConfigurationSerializable {
        @SerializableAs("Location")
        public static class SLocation extends Location implements ConfigurationSerializable {
            public static SLocation deserialize(final Map<String, Object> map) {
                final int x = (int) map.get("x");
                final int y = (int) map.get("y");
                final int z = (int) map.get("z");
                final World w = Bukkit.getWorld((String) map.get("w"));
                return new SLocation(w, x, y, z);
            }

            public SLocation(final World world, final int x, final int y, final int z) {
                super(world, x, y, z);
            }

            @Override
            public Map<String, Object> serialize() {
                final Map<String, Object> map = new HashMap<>();
                map.put("x", getBlockX());
                map.put("y", getBlockY());
                map.put("z", getBlockZ());
                map.put("w", getWorld().getName());
                return map;
            }
        }

        public static SSelection deserialize(final Map<String, Object> map) {
            final SLocation min = (SLocation) map.get("min");
            final SLocation max = (SLocation) map.get("max");
            return new SSelection(min, max);
        }

        private final SLocation min;
        private final SLocation max;

        public SSelection(final SLocation min, final SLocation max) {
            this.min = min;
            this.max = max;
        }

        public SLocation getMinimum() {
            return min;
        }

        public SLocation getMaximum() {
            return max;
        }

        @Override
        public Map<String, Object> serialize() {
            final Map<String, Object> map = new HashMap<>();
            map.put("min", min);
            map.put("max", max);
            return map;
        }
    }

    @Override
    public void onEnable() {
        SSelection sel;
        if (getConfig().contains("sel"))
            sel = (SSelection) getConfig().get("sel");
        else {
            final World w = Bukkit.getWorlds().get(0);
            final SLocation min = new SLocation(w, 1, 2, 3);
            final SLocation max = new SLocation(w, 4, 5, 6);
            getConfig().set("sel", sel = new SSelection(min, max));
            saveConfig();
        }
        System.out.println("min = " + sel.getMinimum());
        System.out.println("max = " + sel.getMaximum());
    }

    @Override
    public void onLoad() {
        ConfigurationSerialization.registerClass(SLocation.class, "Location");
        ConfigurationSerialization.registerClass(SSelection.class, "Selection");
    }
}