启动服务器时，拒绝加载我的插件并出现错误：
Could not load 'plugins\TownTheServer-1.0-SNAPSHOT.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: main class `me.fixegg.towntheserver.CityCreateCommand' does not extend JavaPlugin
at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:76) ~[spigot-1.16.5.jar:3096a-Spigot-9fb885e-af1a232]
at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:145) ~[spigot-1.16.5.jar:3096a-Spigot-9fb885e-af1a232]
at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:394) ~[spigot-1.16.5.jar:3096a-Spigot-9fb885e-af1a232]
at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:301) ~[spigot-1.16.5.jar:3096a-Spigot-9fb885e-af1a232]
at org.bukkit.craftbukkit.v1_16_R3.CraftServer.loadPlugins(CraftServer.java:381) ~[spigot-1.16.5.jar:3096a-Spigot-9fb885e-af1a232]
at net.minecraft.server.v1_16_R3.DedicatedServer.init(DedicatedServer.java:224) ~[spigot-1.16.5.jar:3096a-Spigot-9fb885e-af1a232]
at net.minecraft.server.v1_16_R3.MinecraftServer.w(MinecraftServer.java:928) ~[spigot-1.16.5.jar:3096a-Spigot-9fb885e-af1a232]
at net.minecraft.server.v1_16_R3.MinecraftServer.lambda$0(MinecraftServer.java:273) ~[spigot-1.16.5.jar:3096a-Spigot-9fb885e-af1a232]
at java.lang.Thread.run(Thread.java:831) [?:?]
Caused by: java.lang.ClassCastException: class me.fixegg.towntheserver.CityCreateCommand
at java.lang.Class.asSubclass(Class.java:3853) ~[?:?]
at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:74) ~[spigot-1.16.5.jar:3096a-Spigot-9fb885e-af1a232]
我的代码：
1) CityCreateCommand.java:
package me.fixegg.towntheserver;
import org.bukkit.Chunk;
import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import java.util.HashMap;
import java.util.Map;
public class CityCreateCommand implements CommandExecutor {
private final Map<String, Chunk> cityChunks;
public CityCreateCommand() {
this.cityChunks = new HashMap<>();
}
@Override
public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
if (!(sender instanceof Player)) {
sender.sendMessage("This command can only be executed by a player.");
return true;
}
if (args.length != 1) {
sender.sendMessage("Usage: /t citycreate <cityName>");
return true;
}
Player player = (Player) sender;
String cityName = args[0];
Chunk chunk = player.getLocation().getChunk();
cityChunks.put(cityName, chunk);
sender.sendMessage("City '" + cityName + "' created with coordinates: " +
"X: " + chunk.getX() + ", Z: " + chunk.getZ());
return true;
}
// Run this method periodically to check if players are standing on the saved city chunks
public void checkCityChunks() {
for (Map.Entry<String, Chunk> entry : cityChunks.entrySet()) {
String cityName = entry.getKey();
Chunk chunk = entry.getValue();
for (Player player : chunk.getWorld().getPlayers()) {
if (player.getLocation().getChunk().equals(chunk)) {
System.out.println(player.getName() + " is in city: " + cityName);
}
}
}
}
}
2）plugin.yml：
name: CityCreateCommand
version: 1.0
main: me.fixegg.towntheserver.CityCreateCommand
api-version: '1.16'
# Chat Command Description /t citycreate
commands:
citycreate:
description: Create new Town on player position
aliases: [cc]
usage: /t citycreate <cityName>
# Rights for command
permissions:
towntheserver.citycreate:
description: Allows the player to use the command /t citycreate
default: true
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>me.fixegg</groupId>
<artifactId>TownTheServer</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<name>TownTheServer</name>
<properties>
<java.version>1.8</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>3.2.4</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<createDependencyReducedPom>false</createDependencyReducedPom>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
<repositories>
<repository>
<id>spigotmc-repo</id>
<url>https://hub.spigotmc.org/nexus/content/repositories/snapshots/</url>
</repository>
<repository>
<id>sonatype</id>
<url>https://oss.sonatype.org/content/groups/public/</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>org.spigotmc</groupId>
<artifactId>spigot-api</artifactId>
<version>1.16.5-R0.1-SNAPSHOT</version>
<scope>provided</scope>
</dependency>
</dependencies>
</project>.
我尝试自己寻找答案并解决这个问题，但没有成功。我的 Java 运行时没有检测到任何语法错误，编译也成功。我不知道问题是什么，所以我很高兴得到任何答案，祝你一切顺利！
JavaPluginpublic class TownTheServer extends JavaPlugin {
@Override
public void onEnable() {
getCommand("citycreate").setExecutor(new CityCreateCommand());
}
}
然后，编辑
plugin.ymlmain: me.fixegg.towntheserver.TownTheServer