Main Class and Skill classes

ClassEXAMPLE.java

package xyz.raitaki.CandyHunters.Class.Classes;

import org.bukkit.entity.Player;
import xyz.raitaki.CandyHunters.Class.ClassMain;
import xyz.raitaki.CandyHunters.Skill.Skills.TestSkill;

public class TestClass extends ClassMain {

    public TestClass(Player p){
        super(p);
        addSkill(0, new TestSkill(this));
    }

    @Override
    public String getName() {
        return "TestClass";
    }

    @Override
    public TYPE getType() {
        return TYPE.WILDLING;
    }
}

ClassMain.java

package xyz.raitaki.CandyHunters.Class;

import lombok.Getter;
import org.bukkit.entity.Player;
import xyz.raitaki.CandyHunters.Skill.SkillMain;

import java.util.ArrayList;
import java.util.List;

public abstract class ClassMain {

    public ClassMain(Player p){
        player = p;
    }

    @Getter public Player player;

    @Getter public List<SkillMain> skills = new ArrayList<>();

    public abstract String getName();

    public abstract TYPE getType();

    public void useSkill(Integer slot){
        skills.get(slot).useSkill();
    }

    public void addSkill(Integer slot, SkillMain skill){
        skills.add(slot, skill);
    }

    public enum TYPE{WILDLING, CYBERLING, SUBCLASS}
}

SkillEXAMPLE.java

package xyz.raitaki.CandyHunters.Skill.Skills;

import org.bukkit.Bukkit;
import xyz.raitaki.CandyHunters.Class.ClassMain;
import xyz.raitaki.CandyHunters.Skill.SkillMain;

public class TestSkill extends SkillMain {

    public TestSkill(ClassMain cClass) {
        super(cClass);
    }

    @Override
    public void skill() {
        Bukkit.broadcastMessage("You used your skill");
        startCooldown();
    }

    @Override
    public String getSkillName() {
        return null;
    }

    @Override
    public int getCooldown() {
        return 3;
    }

    @Override
    public boolean canUse() {
        return isCanuse();
    }
}

SkillMain.java

package xyz.raitaki.CandyHunters.Skill;

import lombok.Getter;
import lombok.Setter;
import org.bukkit.Bukkit;
import org.bukkit.entity.Player;
import org.bukkit.scheduler.BukkitRunnable;
import xyz.raitaki.CandyHunters.Class.ClassMain;
import xyz.raitaki.CandyHunters.Main;

public abstract class SkillMain {

    public SkillMain(ClassMain cClass){
        this.cClass = cClass;
    }

    @Getter public ClassMain cClass;

    @Getter @Setter public boolean canuse = true;

    public abstract void skill();

    public abstract String getSkillName();

    public abstract int getCooldown();

    public abstract boolean canUse();

    public void useSkill(){
        skill();
    }

    public void startCooldown(){
        canuse = false;
        new BukkitRunnable() {
            @Override
            public void run() {
                canuse = true;
            }
        }.runTaskLater(Main.getInstance(), getCooldown() * 20L);
    }
}