Baksovic

public class ZDBlocks extends JavaPlugin implements Listener{
    List<Block> BlocksList = new ArrayList<Block>();
    HashMap<Material, Integer> BlockDurabilityList = new HashMap<Material, Integer>();

    public void onEnable() {
        getServer().getPluginManager().registerEvents(this, this);
        BlockDurabilityList.put(Material.DIRT, 200);
        BlockDurabilityList.put(Material.GRASS, 200);
        BlockDurabilityList.put(Material.GLASS, 120);
        BlockDurabilityList.put(Material.WOOD, 50);
        BlockDurabilityList.put(Material.LOG, 30);
        BlockDurabilityList.put(Material.WOODEN_DOOR, 20);
        BlockDurabilityList.put(Material.IRON_DOOR, 10);
        BlockDurabilityList.put(Material.OBSIDIAN, 10);
        new BukkitRunnable() {

            @Override
            public void run() {
                Collection<? extends Player> PlayerList = getServer().getOnlinePlayers();
                Collection<Entity> EntityList;
                for (Player player : PlayerList){
                    if (player.getGameMode() == GameMode.CREATIVE)
                        return;
                    EntityList = player.getNearbyEntities(16.0D, 16.0D, 16.0D);
                    for (Entity entity : EntityList){

                        if (entity.isDead())
                            return;

                        if (entity.getType() == EntityType.ZOMBIE && ((LivingEntity) entity).getTargetBlock((Set<Material>) null, 2).getType() != Material.AIR)
                            BlocksList.add(((LivingEntity) entity).getTargetBlock((Set<Material>) null, 2));
                    }
                }
            }}.runTaskTimer(this, 0, 20);

        new BukkitRunnable() {
            @Override
            public void run(){
                for (Block block : BlocksList)
                    BreakBlock(block);
                BlocksList.removeAll(BlocksList);
            }}.runTaskTimer(this, 0, (long) (Math.random() * 30) + 15);
    }

    protected void BreakBlock(Block block){

        Location loc = block.getLocation();
        Material material = block.getType();
        int RandomValue = 1000;
        int BlockDurability = 20;

        List<Material> BlockList = new ArrayList<Material>();
        BlockList.add(Material.AIR);
        BlockList.add(Material.BEDROCK);

        if (BlockDurabilityList.containsKey(material))
            BlockDurability = BlockDurabilityList.get(material);

        if (BlockList.contains(material))
            return;

        if (Math.random() * RandomValue <= BlockDurability){
            loc.getWorld().playEffect(loc, Effect.ZOMBIE_DESTROY_DOOR, 0);
            block.breakNaturally();
        }
        else
            loc.getWorld().playSound(loc, Sound.ZOMBIE_WOOD, 1.0F, 1.0F);
    }
}