一个自定义注释的例子

import java.lang.annotation.*;import java.lang.reflect.*;@Retention(RetentionPolicy.RUNTIME)@Target(ElementType.METHOD)@interface MyAnn {String name() ;String event();// 方法执行前的事件public static final String METHOD_BEFORE = "METHOD_BEFORE";// 方法执行后的事件public static final String METHOD_END = "METHOD_END";}public class Demo{@MyAnn(name="test",event=MyAnn.METHOD_BEFORE)public void test(){}public static void main(String [] args) throws Exception{Method[] ms=Class.forName("Demo").getMethods();for(int i=0;i<ms.length;i++){boolean tmp=ms[i].isAnnotationPresent(MyAnn.class);if(tmp){MyAnn ma=ms[i].getAnnotation(MyAnn.class);System.out.println(ma.name()+"  "+ma.event());}}}}