Jvm Hook Framework

简体中文

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Desc

JVM Hook Framework is designed for injecting java classes with friendly apis using SpongePowered/mixin

Using

You need add Maven Central and https://repo.spongepowered.org/repository/maven-public/ into your repositories.

plugins {
    id 'java-library'
}

repositories {
    mavenCentral()
    maven { url = 'https://repo.spongepowered.org/repository/maven-public/' }
    maven { url = 'https://files.minecraftforge.net/maven/' }
}

dependencies {
    api 'io.github.karlatemp.jhf:api:<version>'
}

Developing a plugin

Project setup

• Create a new class named myjhfplugin.Startup (or other you like)
• Create a new file in project resources named jhf-main.txt
• Write myjhfplugin.Start in jhf-main.txt
• Add a static method in myjhfplugin.Startup named launch with no parameter and void return type

  private static void launch() throws Throwable {}

Using mixin

You need create a class module of class you want to inject.

import org.spongepowered.asm.mixin.Mixin;
import org.spongepowered.asm.mixin.Overwrite;

@Mixin(targets = "testunit.RunTester")
public class MixinRunTester {
    @Overwrite
    public static void error() {
    }
}

Then, you need create a mixin configuration file in your project resources. Suggested path format is ${project-name}/mixin/${config-name}.json

{
  "minVersion": 0,
  "package": "tester.mixin",
  // The package storing mixin classes
  "mixins": [
    "MixinRunTester"
  ],
  // Class name that relative to ${package}
  "client": [],
  // no effect
  "server": []
  // no effect
}

In your Plugin Main Point add following code

public class MainPlugin {
    private static void launch() throws Throwable {
        Mixins.addConfiguration("myplugin/mixin/main.json");
    }
}

Example: MixinRunTester

Listen JavaLangReflectInvokeEvent

JavaLangReflectInvokeEvent will broadcast when application invoking reflection of java.lang.reflect.

JavaLangReflectInvokeEvent.EVENT_LINE.register(EventPriority.NORMAL,event-> {
    if (event.target instanceof Method) {
        if (event.target.getDeclaringClass().getName().endsWith("EskPermissionDenied")) {
            throw new IllegalAccessException("Permission Denied");
        }
    }
});

Modify bytecodes

When a new class before loading, a TransformBytecodeEvent will broadcast to event-pipeline.

Listen and modify TransformBytecodeEvent.bytecode to change bytecode with the lowest way.

Find an example

The folder tester is a plugin for JvmHookFramework Testing. You can refer to it to write your own plugin.

Plugin configuration

JHF using SpongePowered/Configuration to manage configurations. Using it by

public class Main {
    public static final File DATA_FOLDER = JvmHookFramework.getInstance().getDataFolder("my-plugin");
    public static final HoconConfigurationLoader LOADER = JvmHookFramework.getInstance().newConfigLoader(
            ConfigurationOptions.defaults()
                    .shouldCopyDefaults(true)
            ,
            new File(DATA_FOLDER).toPath()
    );
}