实例化注释

/*nowjava.com - 时  代  Java 提 供*/


//package com.nowjava;

import java.lang.annotation.Annotation;

import java.lang.reflect.InvocationHandler;

import java.lang.reflect.Method;

import java.lang.reflect.Proxy;


public class Main {

    public static void main(String[] argv) throws Exception {

        Class annotationClass = String.class;

        System.out.println(instantiateAnnotation(annotationClass));

    }


    public static Annotation instantiateAnnotation(

            final Class<? extends Annotation> annotationClass) {

        // source http://stackoverflow.com/questions/2786292/is-it-possible-to-instantiate-a-java-annotation-given-a-class-extends-annotatio
//来自 时   代    Java - nowjava.com

        return (Annotation) Proxy.newProxyInstance(

                annotationClass.getClassLoader(),

                new Class[] { Annotation.class }, new InvocationHandler() {

                    @Override

                    public Object invoke(Object proxy, Method method,

                            Object[] args) {

                        if (method.getName().equals("hashCode")) {

                            return annotationClass.getName().hashCode();

                        } else if (method.getName().equals("toString")) {

                            return "[AnnotationObj:"

                                    + annotationClass.getName() + "]";

                        } else if (method.getName().equals("equals")) {

                            if (args[0] == null) {