package com.bili;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.reflect.Method;

//ElementType.METHOD 作用在方法上
//RetentionPolicy.RUNTIME 注解的生命周期
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)

@interface VIP{
    String level() default "";
}

class Dog{
    @VIP(level = "3")
    public void one(){

    }
}
public class test {
    public static void main(String[] args) throws NoSuchMethodException {
        //获得这个类的字节码
        Class<?> aClass = Dog.class;
        //得到Dog类中one方法
        Method one = aClass.getMethod("one");
        //获得one中的注解        
        VIP vip = one.getAnnotation(VIP.class);
        System.out.println(vip.level());
    }
}