First Java Plugin

Build a minimal HelloWorld plugin from scratch. At the end of this page, you will have a .jar file that Nukkit-MOT can load.

Where You Are

Step 1 of 4: create the project, add the dependency, and build the first plugin jar.

Next: Plugin Basics

What You Need

• Java 17 or newer
• IntelliJ IDEA Community or another Java IDE
• Maven
• A local Nukkit-MOT server folder for the next page

Create a Maven Project

Create a standard Maven project and use values similar to these:

Setting	Value
GroupId	com.example
ArtifactId	hello-world-plugin
Name	HelloWorldPlugin
Package	com.example.helloworld
JDK	17

After the project is created, replace pom.xml with this example. The repository URL and dependency coordinates match the current Nukkit-MOT README:

pom.xml

<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.example</groupId>
  <artifactId>hello-world-plugin</artifactId>
  <version>1.0.0</version>
  <name>HelloWorldPlugin</name>

  <properties>
    <maven.compiler.release>17</maven.compiler.release>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <repositories>
    <repository>
      <id>repo-lanink-cn</id>
      <url>https://repo.lanink.cn/repository/maven-public/</url>
    </repository>
  </repositories>

  <dependencies>
    <dependency>
      <groupId>cn.nukkit</groupId>
      <artifactId>Nukkit</artifactId>
      <version>MOT-SNAPSHOT</version>
      <scope>provided</scope>
    </dependency>
  </dependencies>
</project>

Project Layout

Create the following files:

hello-world-plugin/
├─ pom.xml
└─ src/
   └─ main/
      ├─ java/
      │  └─ com/
      │     └─ example/
      │        └─ helloworld/
      │           └─ HelloWorldPlugin.java
      └─ resources/
         └─ plugin.yml

Create the Main Class

Create src/main/java/com/example/helloworld/HelloWorldPlugin.java:

src/main/java/com/example/helloworld/HelloWorldPlugin.java

package com.example.helloworld;

import cn.nukkit.plugin.PluginBase;

public final class HelloWorldPlugin extends PluginBase {

    @Override
    public void onEnable() {
        this.getLogger().info("Hello from my first Nukkit-MOT plugin!");
    }
}

onEnable() is the first lifecycle method most plugin authors use. When the server enables your plugin successfully, this method is called.

Create plugin.yml

Create src/main/resources/plugin.yml:

src/main/resources/plugin.yml

name: HelloWorldPlugin
main: com.example.helloworld.HelloWorldPlugin
version: "1.0.0"
api: ["1.0.0"]
author: YourName
description: My first Nukkit-MOT plugin

This file is required. Nukkit-MOT reads it from the jar and uses it to locate your plugin entry class.

Check the main field carefully

main must exactly match your Java package name and class name. If it points to the wrong class, the plugin will not load.

Build the Plugin Jar

Run this command in the project root:

mvn clean package

If you prefer IntelliJ IDEA, open the Maven panel and run clean, then package.

The output is usually:

target/hello-world-plugin-1.0.0.jar

Because plugin.yml is under src/main/resources/, Maven copies it into the jar automatically.

Before You Continue

• If Maven cannot resolve cn.nukkit:Nukkit:MOT-SNAPSHOT, re-check the repository URL and your network connection.
• If the project builds successfully, continue to Plugin Basics.