package com.anno;import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;@Retention(RetentionPolicy.RUNTIME) // 表示注解在运行时依然存在
@Target(ElementType.METHOD) // 表示注解可以使用在方法上
public @interface CallAnnotation {String phone() default "某某";; // 表示注解须要一个参数，默认值为"某某"

}

package com.anno;public class Person {public void call( String phone) {System.out.println("call=>"+phone);}@CallAnnotationpublic void callByAnnotationDefault(String phone){System.out.println("callByAnnotationDefault=>"+phone);}@CallAnnotation(phone = "张三")public void callByUserAnnotation(String phone){System.out.println("callUserAnnotation=>"+phone);}}

package com.anno;import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;public class TestAnno {public static void main(String[] args)throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {Person person = new Person(); //创建person对象Method[] methods = Person.class.getDeclaredMethods(); //得到所有方法for (Method meth : methods) {CallAnnotation annoTemp = null;annoTemp = meth.getAnnotation(CallAnnotation.class); //得到注解对象System.out.println("调用方法名称:" + meth.getName());System.out.println("注释的对象信息:" + annoTemp);if (annoTemp != null) { //如果注解对象不为空，将参数值设为注解的值
                meth.invoke(person, annoTemp.phone());} else {meth.invoke(person, "李四"); //如果注解对象为空，单独设置参数值
            }System.out.println();}}}