Question

好的，所以如果玩家被僵尸杀死（例子）我试图获取暴徒名称，但我总是得到一个NullPointerException。

我确信我在代码中搞砸了一些东西，但我现在真的很头疼，我无法找到问题所在。

堆栈追踪：

以下是代码：

package me.parat26.listeners;

import me.parat26.utils.SettingsManager;

import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.entity.EntityDamageEvent;
import org.bukkit.event.entity.EntityDamageEvent.DamageCause;
import org.bukkit.event.entity.EntityDeathEvent;
import org.bukkit.event.entity.PlayerDeathEvent;

public class PlayerDeathCauses implements Listener
{
    SettingsManager config = SettingsManager.getInstance();

    @EventHandler
    public void checkDeathCauses(EntityDeathEvent e)
    {
            Player p = (Player) e.getEntity();
            String victim = p.getDisplayName();

            EntityDamageEvent entityDamageCause = p.getLastDamageCause();
            DamageCause damage = entityDamageCause.getCause();

            String mob = e.getEntity().getType().getName();

            if (damage == DamageCause.DROWNING)
            {
                String death = config.parse("death.drowned").replace("<player>", victim);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.ENTITY_ATTACK)
            {
                String death = config.parse("death.mob").replace("<player>", victim).replace("<mob>", mob);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.ENTITY_EXPLOSION)
            {
                String death = config.parse("death.mob-explosion").replace("<player>", victim).replace("<mob>", mob);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.FALL)
            {
                String death = config.parse("death.fall").replace("<player>", victim);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.FALLING_BLOCK)
            {
                String death = config.parse("death.falling-block").replace("<player>", victim);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.FIRE)
            {
                String death = config.parse("death.fire").replace("<player>", victim);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.LAVA)
            {
                String death = config.parse("death.lava").replace("<player>", victim);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.LIGHTNING)
            {
                String death = config.parse("death.lightning").replace("<player>", victim);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.MAGIC)
            {
                String death = config.parse("death.magic").replace("<player>", victim);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.POISON)
            {
                String death = config.parse("death.poison").replace("<player>", victim);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.PROJECTILE)
            {
                String death = config.parse("death.projectile").replace("<player>", victim).replace("<mob>", mob);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.STARVATION)
            {
                String death = config.parse("death.starved").replace("<player>", victim);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.SUFFOCATION)
            {
                String death = config.parse("death.suffocated").replace("<player>", victim);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.SUICIDE)
            {
                String death = config.parse("death.suicide").replace("<player>", victim);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.VOID)
            {
                String death = config.parse("death.void").replace("<player>", victim);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
            else if (damage == DamageCause.WITHER)
            {
                String death = config.parse("death.wither").replace("<player>", victim);
                ((PlayerDeathEvent) e).setDeathMessage(death);
            }
    }
}

Answer 1

您的错误是将e.getEntity()类型转换为(Player)类型，而实体不是播放器。在将e.getEntity()转换为(Player)之前，您需要进行检查以确保Entity属于Player类型。

if(e.getEntity() instanceof Player){
Player p = (Player)e.getEntity();
}

否则每当羊，牛或其他东西死亡时，它会尝试将Cow实体强制转换为Player实体，这显然不会起作用。

另外，我不知道它实际上是否是Cow类型，这只是一个例子。请务必遵循API！

希望这有帮助！

Answer 2

基于此堆栈跟踪，您将获得ClassCastException。这意味着您正在尝试转换无效的类。您正试图将e.getEntity（）强制转换为播放器

Player p = (Player) e.getEntity();

但是这个调用返回的实例不是Player类，而是CraftBat类。如果您尝试

，您可以看到返回的内容

System.out.println(e.getEntity.getClass());

或在IDE中尝试调试，看看它在Debug窗口中的类。所以这适用于这种情况：

CraftBat craftBat = (CraftBat)e.getEntity();

但它很可能不是你要找的东西。

Bukkit无法获得杀死玩家的暴徒名字

2 个答案: