Force the end credits on an unsuspecting player.

ForceEnd.java

package com.comphenix.example;

import net.minecraft.server.v1_8_R3.EntityPlayer;
import net.minecraft.server.v1_8_R3.PacketPlayOutGameStateChange;

import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.craftbukkit.v1_4_R1.entity.CraftPlayer;
import org.bukkit.entity.Player;
import org.bukkit.event.Listener;
import org.bukkit.plugin.java.JavaPlugin;

public class ForceEnd extends JavaPlugin implements Listener {
    @Override
    public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
        if (sender instanceof Player) {
            displayCredits((Player) sender);
        } else {
            sender.sendMessage(ChatColor.RED + "Must be a player.");
        }
        
        return true;
    }
    
    public void showMinecraftCredits(Player p){
		CraftPlayer craft = (CraftPlayer)p;
        EntityPlayer nms = craft.getHandle();
        
        nms.viewingCredits = true;
        nms.playerConnection.sendPacket(new PacketPlayOutGameStateChange(4, 0.0F));
	}
}