Project

Code Generation Library

CGLIB outputs generated classes. Byte code generation and class file format manipulation is hidden in static methods. It was designed to implement Transparent Persistence for JAVA, but can be used to implement aspects like Security or Validation.

Simple example : Implement MethodInterceptor

public class Trace implements MethodInterceptor{

   private static Trace trace = new Trace();
    
   public boolean invokeSuper( Object obj, Method method,
                        Object args[]) throws  Throwable{
//invoke supper in generated code
         System.out.println("before: " +  method );
      return true ; 
     }
   public Object afterReturn(
                             Object obj, Method method,
                             Object args[],boolean invokedSuper, 
                             Object retValFromSuper,Throwable e 
                                   )throws Throwable{
//print "this" and method signature  
            System.out.println("after: " +  method );
       return retValFromSuper;
     }
 public static Object newInstance(Class clazz){
//generate code
        return Enhancer.enhance(clazz, null, trace);
   }
 }   
 

 List list = (List)Trace.newInstance( Vector.class );
 list.add( "TEST" );