Java 尝试在聊天事件（Minecraft、Spigot）上设置玩家displayname时出错

我对Java和编程Minecraft插件相当陌生。我希望聊天侦听器检查一下，玩家的名字在配置中，然后将显示名称设置为该名称，但是如果玩家的名字不在配置中，那么我希望它只设置玩家的名字

这是我的聊天侦听器：

package me.purp.servercore.listeners;

import org.bukkit.Bukkit;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.AsyncPlayerChatEvent;

import me.purp.servercore.Main;
import me.purp.servercore.utils.Utils;

public class ServerChat implements Listener
{
    private Main plugin;

    public ServerChat(Main plugin)
    {
        Bukkit.getPluginManager().registerEvents(this, plugin);
    }

    @EventHandler
    public void Chat(AsyncPlayerChatEvent event)
    {

        String message = event.getMessage();

        Player player = event.getPlayer();

        if (!plugin.getConfig().contains(player.getName())) {
            event.setFormat(Utils.color("&7" + player.getDisplayName() + " &7&l» &r" + message));
        } else if (plugin.getConfig().contains(player.getName())) {
            event.setFormat(Utils.color("&7" + plugin.getConfig().getString(player.getName()) + " &7&l» &r" + message));
        }
    }

}

这是我的昵称课：

package me.purp.servercore.commands;

import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.configuration.file.FileConfiguration;
import org.bukkit.entity.Player;

import me.purp.servercore.Main;
import me.purp.servercore.utils.Utils;

public class PlayerNick implements CommandExecutor
{
    private Main plugin;

    public PlayerNick(Main plugin)
    {
        this.plugin = plugin;

        plugin.getCommand("nick").setExecutor(this);
    }

    public boolean onCommand(CommandSender sender, Command command, String label, String[] args)
    {
        FileConfiguration config = plugin.getConfig();

        if (!(sender instanceof Player))
        {
            sender.sendMessage(Utils.color(config.getString("PlayerEntityFalse")));
            return true;
        }

        Player player = (Player) sender;

        if (player.hasPermission("core.nick"))
        {
            if (args.length == 0)
            {
                player.sendMessage(Utils.color("&cYou cannot have a blank nickname!"));
                return true;
            }

            String nick = "";
            for (String arg : args)
            {
                nick += arg + " ";
            }

            player.sendMessage(Utils.color("&7Your nickname is now: " + nick));
            config.set(player.getName(), nick);
            plugin.saveConfig();
        }

        return false;
    }
}

这是我的错误：

Could not pass event AsyncPlayerChatEvent to Core v0.2
org.bukkit.event.EventException: null
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-1.12.2.jar:git-Spigot-2cf50f0-8166d17]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1.12.2.jar:git-Spigot-2cf50f0-8166d17]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:500) [spigot-1.12.2.jar:git-Spigot-2cf50f0-8166d17]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:482) [spigot-1.12.2.jar:git-Spigot-2cf50f0-8166d17]
        at net.minecraft.server.v1_12_R1.PlayerConnection.chat(PlayerConnection.java:1319) [spigot-1.12.2.jar:git-Spigot-2cf50f0-8166d17]
        at net.minecraft.server.v1_12_R1.PlayerConnection.a(PlayerConnection.java:1257) [spigot-1.12.2.jar:git-Spigot-2cf50f0-8166d17]
        at net.minecraft.server.v1_12_R1.PacketPlayInChat$1.run(PacketPlayInChat.java:39) [spigot-1.12.2.jar:git-Spigot-2cf50f0-8166d17]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:?]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:?]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:?]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:?]
        at java.lang.Thread.run(Unknown Source) [?:?]
Caused by: java.lang.NullPointerException
        at me.purp.servercore.listeners.ServerChat.Chat(ServerChat.java:29) ~[?:?]
        at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
        at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:?]
        at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:?]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:?]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[spigot-1.12.2.jar:git-Spigot-2cf50f0-8166d17]
        ... 11 more

---

正如Carlos在这篇文章中的评论所说：

您尚未在

ServerChat

类中设置

this.plugin=plugin

---

第29行：

如果（！plugin.getConfig（）包含（player.getName（））{

所以

• 插件

  或

• plugin.getConfig（）

  或

• player

尝试打印出这些变量并告诉我们哪一个是空的

我的朋友们：

---

可能您没有使用saveDefaultConfig（）保存配置在onEnable方法中。

plugin

不应该为空，因为注册侦听器时构造函数应该有问题。

player

通常不为空，所以问题应该在配置中。

似乎该类中从未设置过

plugin

，构造函数中可能缺少此选项……噢，哇它，你说的对，我把它添加到我为你做贡献的帖子中！但是请留下你的解释-这是在类

ServerChat

中查找错误的方法，字段

插件

从未初始化过（就像在

PlayerNick

的构造函数中一样）

Caused by: java.lang.NullPointerException
        at me.purp.servercore.listeners.ServerChat.Chat(ServerChat.java:29)