hadoop29---自定义注解

自定义注解：

package cn.itcast_04_springannotation.userdefinedannotation.annotation;

import java.lang.annotation.ElementType;

import java.lang.annotation.Retention;

import java.lang.annotation.RetentionPolicy;

import java.lang.annotation.Target;

import org.springframework.stereotype.Component;

//自定义注解的规范

@Target({ ElementType.TYPE }) //表示@RpcService这个注解是用在类上的，METHOD表示注解用在方法上的。

@Retention(RetentionPolicy.RUNTIME) //注解的生命周期，VM将在运行期保留注解，spring会把这个注解标注的类做实例化。

@Component //让spring去扫描

public @interface RpcService {

    String value();//@RpcService("HelloServicebb")的HelloServicebb

}

service接口

package cn.itcast_04_springannotation.userdefinedannotation.service;

public interface HelloService {

    String hello(String name);

}

service实现：

package cn.itcast_04_springannotation.userdefinedannotation.service.impl;

import cn.itcast_04_springannotation.userdefinedannotation.annotation.RpcService;

import cn.itcast_04_springannotation.userdefinedannotation.service.HelloService;

@RpcService("HelloServicebb")

public class HelloServiceImpl implements HelloService {

    public String hello(String name) {

        return "Hello! " + name;

    }

    public void test(){

        System.out.println("test");

    }

}

测试：

package cn.itcast_04_springannotation.userdefinedannotation.test;

import java.lang.reflect.Method;

import java.util.Map;

import org.springframework.beans.BeansException;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.context.ApplicationContext;

import org.springframework.context.ApplicationContextAware;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import org.springframework.stereotype.Component;

import cn.itcast_04_springannotation.userdefinedannotation.annotation.RpcService;

import cn.itcast_04_springannotation.userdefinedannotation.service.HelloService;

@Component        //测试Myserver3时注释

public class MyServer implements ApplicationContextAware {

    //如果某个类实现了ApplicationContextAware接口，会在类初始化完成后调用setApplicationContext（）方法进行操作

    @SuppressWarnings("resource")

    public static void main(String[] args) {

        ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("spring2.xml");

        /*<?xml version="1.0" encoding="UTF-8"?>

        <beans xmlns="http://www.springframework.org/schema/beans"

               xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

               xmlns:context="http://www.springframework.org/schema/context"

               xsi:schemaLocation="http://www.springframework.org/schema/beans

               http://www.springframework.org/schema/beans/spring-beans.xsd

               http://www.springframework.org/schema/context

               http://www.springframework.org/schema/context/spring-context.xsd">

               //扫描包，把自定义和不是自定义的注解都加进来

            <context:component-scan base-package="cn.itcast_04_springannotation.userdefinedannotation"/>

        </beans>*/

    }

    public void setApplicationContext(ApplicationContext ctx)

            throws BeansException {

        Map<String, Object> serviceBeanMap = ctx

                .getBeansWithAnnotation(RpcService.class);//拿到标注了自定义注解的对象

        for (Object serviceBean : serviceBeanMap.values()) {

            try {

                //获取自定义注解上的value

                String value = serviceBean.getClass().getAnnotation(RpcService.class).value();

                System.out.println("注解上的value: " + value);

                //反射被注解类，并调用指定方法

                Method method = serviceBean.getClass().getMethod("hello",

                        new Class[] { String.class });

                Object invoke = method.invoke(serviceBean, "bbb");

                System.out.println(invoke);

            } catch (Exception e) {

                e.printStackTrace();

            }

        }

    }

}

测试2：

package cn.itcast_04_springannotation.userdefinedannotation.test;

import java.lang.reflect.Method;

import java.util.Map;

import org.springframework.beans.BeansException;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.context.ApplicationContext;

import org.springframework.context.ApplicationContextAware;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import org.springframework.stereotype.Component;

import cn.itcast_04_springannotation.userdefinedannotation.annotation.RpcService;

import cn.itcast_04_springannotation.userdefinedannotation.service.HelloService;

//@RunWith(SpringJUnit4ClassRunner.class)

//@ContextConfiguration(locations = "classpath:spring2.xml")

//@Component

public class MyServer2 implements ApplicationContextAware {

    @SuppressWarnings("resource")

    public static void main(String[] args) {

        ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("spring2.xml");

        /*<?xml version="1.0" encoding="UTF-8"?>

        <beans xmlns="http://www.springframework.org/schema/beans"

               xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

               xmlns:context="http://www.springframework.org/schema/context"

               xsi:schemaLocation="http://www.springframework.org/schema/beans

               http://www.springframework.org/schema/beans/spring-beans.xsd

               http://www.springframework.org/schema/context

               http://www.springframework.org/schema/context/spring-context.xsd">

            <context:component-scan base-package="cn.itcast_04_springannotation.userdefinedannotation"/>

        </beans>*/

        Map<String, Object> beans = ctx.getBeansWithAnnotation(RpcService.class);

        for(Object obj: beans.values()){

            HelloService hello=(HelloService) obj;

            String hello2 = hello.hello("mmmm");

            System.out.println(hello2);

        }

    }

    /*@Test

    public void helloTest1() {

    System.out.println("开始junit测试……");

    }*/

    public void setApplicationContext(ApplicationContext ctx)

            throws BeansException {

        Map<String, Object> serviceBeanMap = ctx

                .getBeansWithAnnotation(RpcService.class);

        for (Object serviceBean : serviceBeanMap.values()) {

            try {

                Method method = serviceBean.getClass().getMethod("hello",

                        new Class[] { String.class });

                Object invoke = method.invoke(serviceBean, "bbb");

                System.out.println(invoke);

            } catch (Exception e) {

                e.printStackTrace();

            }

        }

    }

}

测试3：

package cn.itcast_04_springannotation.userdefinedannotation.test;

import org.junit.Test;

import org.junit.runner.RunWith;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Component;

import org.springframework.test.context.ContextConfiguration;

import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import cn.itcast_04_springannotation.userdefinedannotation.service.HelloService;

@RunWith(SpringJUnit4ClassRunner.class)

@ContextConfiguration(locations = "classpath:spring2.xml")

@Component

public class MyServer3 {

    @Autowired

    HelloService helloService;

    @Test

    public void helloTest1() {

        System.out.println("开始junit测试……");

        String hello = helloService.hello("ooooooo");

        System.out.println(hello);

    }

}