我的世界Minecraft Mod开发学习笔记 - 实现一个简单的命令Mod

概述

本文使用Forge MDK (Mod Development Kit)实现一个简单的命令Mod用于显示用户输入.

运行环境

• Java 1.8 JDK

• Minecraft Java Edition 1.12.2

• Forge and MDK 1.12.2

安装Forge和MDK

• 从Minecraft Forge官网下载Minecraft Forge - MC 1.12.2 installer和Mod Development Kit (MDK)包.

• 运行Forge installer安装Forge

• 将MDK压缩包解压的指定目录, 例如C:\mdk.

设置Mod项目

在MDK目录下, 运行gradlew setupDecompWorkspace命令以创建如下Mod项目结构

    mdk/
    ├── build/
    ├── gradle/
    │   └── wrapper/
    │       ├── gradle-wrapper.jar
    │       └── gradle-wrapper.properties
    ├── src/
    │   ├── main/
    │       ├── java/
    │       └── resources/
    │           ├── mcmod.info
    │           └── pack.mcmeta
    ├── build.gradle
    ├── gradlew
    └── gradlew.bat

设置Gradle build文件

编辑build.gradle并修改version, group和archivesBaseName

  version = "1.0.0"
  group= "minecraftfun"
  archivesBaseName = "echo-cmd-mod"

修改 mod 信息

编辑 mcmod.info以修改modid, name和description.

  "modid": "echocmdmod",
  "name": "Echo Command Mod",
  "description": "A command mod echoes user inputs",

提示: modid 只能使用小写字母.

创建command Java类

src/main/java/minecraftfun/EchoCommand.java

package minecraftfun;

import net.minecraft.command.CommandBase;
import net.minecraft.command.CommandException;
import net.minecraft.command.ICommandSender;
import net.minecraft.server.MinecraftServer;
import net.minecraft.util.text.TextComponentString;
import net.minecraft.util.text.TextFormatting;

public class EchoCommand extends CommandBase {

  @Override
  public void execute(MinecraftServer server, ICommandSender sender, String[] params) throws CommandException {

    EchoCommandMod.logger.info("execute called");

    if (params != null && params.length > 0) {
      for (String param : params) {
        String message = "Echo : " + param;
        TextComponentString text = new TextComponentString(message);
        text.getStyle().setColor(TextFormatting.RED);
        sender.sendMessage(text);
      }
    }
  }

  @Override
  public String getName() {
    return "echo";
  }

  @Override
  public String getUsage(ICommandSender sender) {
    return "command.echo.usage";
  }
}

getUsage方法的返回字符串对应语言文件中的键值.

创建mod Java类

src/main/java/minecraftfun/EchoCommandMod.java

package minecraftfun;

import org.apache.logging.log4j.Logger;

import net.minecraftforge.fml.common.Mod;
import net.minecraftforge.fml.common.Mod.EventHandler;
import net.minecraftforge.fml.common.event.FMLPreInitializationEvent;
import net.minecraftforge.fml.common.event.FMLServerStartingEvent;

@Mod(modid = EchoCommandMod.MODID, name = EchoCommandMod.NAME, version = EchoCommandMod.VERSION)
public class EchoCommandMod {

      public static final String MODID = "echocmdmod";
      public static final String NAME = "Echo Command Mod";
      public static final String VERSION = "1.0.0";

      public static Logger logger;

      @EventHandler
      public void preInit(FMLPreInitializationEvent event)
      {
          logger = event.getModLog();
      }

      @EventHandler
      public void init(FMLServerStartingEvent event)
      {
        logger.info("initalise FMLServerStartingEvent :" + NAME);
        event.registerServerCommand(new EchoCommand());
      }
}

设置resource目录结构

在src/main/resources目录下, 创建如下目录和文件, 将MODID替换为EchoCommandMod.MODID

    src/main/resources/assets/
        └── <MODID>/
              └── lang/
                   └── en_us.lang

修改mod语言文件

src/main/resources/assets/echocmdmod/lang/en_us.lang

  command.echo.usage=/echo <MESSAGE>

运行如下命令以编译Mod

  gradlew build

该命令在build/libs目录下生成[archivesBaseName]-[version].jar文件.

测试Mod

将编译生成的mod jar文件放入Minecraft mods目录(在Windows下为 %appdata%.minecraft\mods), 运行Minecraft, 输入命令/echo some message here.

小结

对Minecraft Mod开发感兴趣的朋友不妨试一试, 所有源代码和mod jar文件也可以从这里下载.