javaassist used in the hibernate

  javaassist opensource framework is the initials of  the"Java Programming Assistant" , it makes Java bytecode manipulation simple and easy. you can manipulate the behaviors of the java the following aspects:
1 soruce code level
2 bytecode level
hibernate use the javaassist to instead to the cglib in version 3.3, its function is similar to the cglib ,it can implement the lazy loading and generate the po objects
for examples:
package antlr;

import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtMethod;




public class TestAntlr {

    public static void main(String[] args) throws Exception {
        ClassPool cp = ClassPool.getDefault();
        CtClass cc = cp.get("antlr.Hello");
        CtMethod m = cc.getDeclaredMethod("say");
//         m.setBody("{System.out.println(\"s\");}");

        m.insertBefore("System.out.println(\"ss\");");
        Class c = cc.toClass();
        Hello h = (Hello)c.newInstance();
        h.say();
       
//         ClassPool cp = ClassPool.getDefault();
//         CtClass cc = cp.get("java.lang.String");
//         CtMethod m = cc.getDeclaredMethod("toString");
////         m.setBody("{System.out.println(\"s\");}");
//
////         m.insertBefore("System.out.println(\"ss\");");
//         Class c = cc.toClass();
//         String h = (String)c.newInstance();
//         h.toString();
       
       
    }
}



package antlr;

class Hello{
public void say() {
        System.out.println("Hello");
    }
}