ExceptionUtils.java

package org.gentoo.java;

import static org.objectweb.asm.Opcodes.ACC_PUBLIC;
import static org.objectweb.asm.Opcodes.ACC_STATIC;
import static org.objectweb.asm.Opcodes.ACC_SUPER;
import static org.objectweb.asm.Opcodes.ALOAD;
import static org.objectweb.asm.Opcodes.ATHROW;
import static org.objectweb.asm.Opcodes.INVOKESPECIAL;
import static org.objectweb.asm.Opcodes.RETURN;
import static org.objectweb.asm.Opcodes.V1_5;

import java.io.File;
import java.io.FileOutputStream;

import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;

public class ExceptionUtils {
	private final static String gentooClassDestination = "target/classes/org/codehaus/groovy/runtime/ExceptionUtils.class";
	
	public static void main(String[] args) {
		
        ClassWriter cw = new ClassWriter(0);
        MethodVisitor mv;

        cw.visit(V1_5, ACC_PUBLIC + ACC_SUPER, "org/codehaus/groovy/runtime/ExceptionUtils", null, "java/lang/Object", null);
        cw.visitSource("ExceptionUtils.java", null);	

        mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
        mv.visitCode();
        Label l0 = new Label();
        mv.visitLabel(l0);
        mv.visitLineNumber(18, l0);
        mv.visitVarInsn(ALOAD, 0);
        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
        mv.visitInsn(RETURN);
        Label l1 = new Label();
        mv.visitLabel(l1);
        mv.visitLocalVariable("this", "Lorg/codehaus/groovy/runtime/ExceptionUtils;", null, l0, l1, 0);
        mv.visitMaxs(1, 1);
        mv.visitEnd();

        mv = cw.visitMethod(ACC_PUBLIC + ACC_STATIC, "sneakyThrow", "(Ljava/lang/Throwable;)V", null, null);
        mv.visitCode();
        Label l2 = new Label();
        mv.visitLabel(l2);
        mv.visitLineNumber(20, l2);
        mv.visitVarInsn(ALOAD, 0);
        mv.visitInsn(ATHROW);
        Label l3 = new Label();
        mv.visitLabel(l3);
        mv.visitLocalVariable("e", "Ljava/lang/Throwable;", null, l2, l3, 0);
        mv.visitMaxs(1, 1);
        mv.visitEnd();

        cw.visitEnd();
        FileOutputStream fos = null;
        
        File f = new File(gentooClassDestination);
        f.getParentFile().mkdirs();
        try {
		fos = new FileOutputStream(f);			
		fos.write(cw.toByteArray());
		fos.close();
	} catch (Exception e) {
		e.printStackTrace();
		}
	}
}