My Firework On Join Plugin

//my package name
package me.OrangeSlimeKing.WhenJoinDoFireork;

//import all entities and spigot-bukkit commands
import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.Color;
import org.bukkit.FireworkEffect;
import org.bukkit.FireworkEffect.Type;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Firework;
import org.bukkit.entity.Player;
import org.bukkit.entity.Player.Spigot;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerJoinEvent;
import org.bukkit.inventory.meta.FireworkMeta;
import org.bukkit.plugin.java.JavaPlugin;

public class Main extends JavaPlugin implements Listener {
	//when server starts
	public void onEnable(){
		getLogger().info("Plugin Successfully Enabled! :^)");

		//Register all events on this page
		Bukkit.getServer().getPluginManager().registerEvents(this, this);

	}
	//when server is closed
	public void onDisable(){
		getLogger().info("Plugin Correctly Disabled! :^(");

	}
	//checks if player has joined if has does next thing
	@EventHandler
	public void onPlayerJoin (final PlayerJoinEvent pje) {
			Bukkit.getServer().getScheduler().scheduleSyncDelayedTask(this, new Runnable()){
				public void run(){

					Firework f = (Firework) pje.getPlayer().getWorld().spawn(pje.getPlayer().getLocation(), Firework.class);
					//details of the firework- firework meta
					FireworkMeta fm = f.getFireworkMeta();
					fm.addEffect(FireworkEffect.builder()
							.flicker(false)
							.trail(true)
							.with(Type.BALL)
							.with(Type.BALL_LARGE)
							.with(Type.STAR)
							.withColor(Color.ORANGE)
							.withFade(Color.FUCHSIA)
							.withColor(Color.YELLOW)
							.withFade(Color.RED)
							.build());
					fm.setPower(2);
					f.setFireworkMeta(fm);
					//Says Welcome to the server %name% after firework is complete
			Player player = (Player) sender;
				player.sendMessage(ChatColor.DARK_PURPLE + "Welcome to the server " + player.getName());
				}
				// }, 20) is the delay (20 ticks)
			}, 20);
	}
}