Dump classes at runtime minecraft server

classdumper.java

java
package com.yourplugin;

import org.bukkit.plugin.java.JavaPlugin;
import java.io.*;
import java.nio.file.*;
import java.lang.instrument.*;
import java.security.ProtectionDomain;


public class ClassDumper extends JavaPlugin {
    @Override
    public void onEnable() {
        try {
            dumpClasses();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void dumpClasses() throws Exception {
        // Create a folder in plugins directory where you will save the classes.
        Path savePath = Paths.get(getDataFolder().getAbsolutePath(), "/dumpedClasses/");
        Files.createDirectories(savePath);

        Instrumentation instrumentation = ByteBuddyAgent.install();
        Class<?>[] classes = instrumentation.getAllLoadedClasses();

        for (Class<?> c : classes) {
            String classFileName = c.getName().replace('.', File.separatorChar) + ".class";
            Path classFilePath = Paths.get(savePath.toString(), classFileName);
            Files.createDirectories(classFilePath.getParent());

            ClassFileTransformer transformer = new ClassFileTransformer() {
                @Override
                public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) {
                    return classfileBuffer;
                }
            };

            try {
                instrumentation.addTransformer(transformer, true);
                instrumentation.retransformClasses(c);
            } finally {
                instrumentation.removeTransformer(transformer);
            }
            Files.write(classFilePath, transformer.transform(c.getClassLoader(), c.getName(), c, c.getProtectionDomain(), ClassPool.getDefault().get(c.getName()).toBytecode()));
        }
    }
}

dependencies.xml

<dependencies>
    <dependency>
        <groupId>net.bytebuddy</groupId>
        <artifactId>byte-buddy</artifactId>
        <version>1.12.6</version>
        <!-- Other vars. -->
    </dependency>
    <dependency>
        <groupId>net.bytebuddy</groupId>
        <artifactId>byte-buddy-agent</artifactId>
        <version>1.12.6</version>
        <!-- Other vars. -->
    </dependency>
    <dependency>
        <groupId>org.javassist</groupId>
        <artifactId>javassist</artifactId>
        <version>3.27.0-GA</version>
    </dependency>
</dependencies>