ClassDumpingTransformer.java

package net.cazzar.corelib.asm.transformers;

import net.minecraft.launchwrapper.IClassTransformer;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.FieldNode;
import org.objectweb.asm.tree.MethodNode;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintStream;

public class ClassDumpingTransformer implements IClassTransformer {
    static File[] outputFile = {new File("fields"), new File("methods")};

    static {
        for (File file : outputFile) {
            if (!file.exists()) try {
                file.createNewFile();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
    }

    PrintStream[] output = new PrintStream[outputFile.length];

    public ClassDumpingTransformer() throws FileNotFoundException {
        for (int i = 0; i < outputFile.length; i++) {
            output[i] = new PrintStream(outputFile[i]);
        }
    }

    @Override
    public byte[] transform(String name, String transformedName, byte[] bytes) {
        if (!transformedName.startsWith("net.minecraft.")) return bytes;

        ClassNode clazz = new ClassNode();
        ClassReader classReader = new ClassReader(bytes);
        classReader.accept(clazz, 0);

        for (PrintStream stream : output) {
            stream.printf("%n#%s%n", transformedName);
        }

        for (FieldNode field : clazz.fields) {
            output[0].printf("%s %s%n", field.name, field.desc);
        }

        for (MethodNode method : clazz.methods) {
            output[1].printf("%s %s%n", method.name, method.desc);
        }

        return bytes;
    }
}