无法传递事件 PlayerJoinEvent

Question

[01:48:25 ERROR]: Could not pass event PlayerJoinEvent to Listeners v1.0.0
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:305) ~[spigot.jar:git-Spigot-c3c767f-33d5de3]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot.jar:git-Spigot-c3c767f-33d5de3]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot.jar:git-Spigot-c3c767f-33d5de3]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.PlayerList.onPlayerJoin(PlayerList.java:272) [spigot.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.PlayerList.a(PlayerList.java:156) [spigot.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.LoginListener.b(LoginListener.java:109) [spigot.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.LoginListener.c(LoginListener.java:41) [spigot.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.NetworkManager.a(NetworkManager.java:159) [spigot.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.ServerConnection.c(ServerConnection.java:82) [spigot.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.MinecraftServer.z(MinecraftServer.java:800) [spigot.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.DedicatedServer.z(DedicatedServer.java:316) [spigot.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.MinecraftServer.y(MinecraftServer.java:634) [spigot.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:537) [spigot.jar:git-Spigot-c3c767f-33d5de3]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_211]
Caused by: java.lang.NullPointerException
        at me.spoonle.listeners.join.JoinListener.onJoin(JoinListener.java:30) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_211]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_211]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:301) ~[spigot.jar:git-Spigot-c3c767f-33d5de3]
        ... 14 more

控制台错误消息。

package me.spoonle.listeners.join;

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

import me.spoonle.listeners.Main;
import me.spoonle.listeners.Utils.Utils;

public class JoinListener implements Listener {

    private Main plugin;

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

        Bukkit.getPluginManager().registerEvents(this, plugin);
    }

    @EventHandler
    public void onJoin(PlayerJoinEvent e) {
        Player p = e.getPlayer();

        if (!p.hasPlayedBefore()) {
              e.setJoinMessage(Utils.chat(plugin.getConfig().getString("FirstJoinMessage").replace("%player%", p.getName())));
        } else {
            e.setJoinMessage(Utils.chat(plugin.getConfig().getString("JoinMessage").replace("%player%", p.getName())));
        }
    }
    @EventHandler
    public void onQuit(PlayerQuitEvent q) {
        Player p = q.getPlayer();

        q.setQuitMessage(Utils.chat(plugin.getConfig().getString("QuitMessage").replace("%palyer%", p.getName())));
    }

}

这是我的加入消息和退出消息代码。为什么它不能完全工作？我错过了什么？我需要添加一些东西吗？我正在关注 youtube 上的教程，并完全按照步骤操作，并用他们的代码检查了我的代码三倍，结果是一样的，所以我很困惑。

Answer 1

显然，您的插件在第 30 列的 JoinListener 中抛出了一个 Nullpointer。 我猜可能是plugin.getConfig().getString("JoinMessage")

来自官方 Spigot docs 1.14 文档：

FileConfiguration.getString(String path)

如果字符串不存在但已指定默认值， 这将返回默认值。如果字符串不存在并且 没有指定默认值，这将返回 null。

您的配置中似乎不存在“JoinMessage”条目。