Spring AOP-05-引介加強 IntroductionInterceptor

引介加強的目標是在目標類中添加一些新的方法和屬性。以Waiter類爲例，如今想給其添加一個Management接口中的manage()方法而不修改Waiter類的代碼。

一、須要加強的類

package com.test.springadvicetype;

import org.springframework.stereotype.Component;

import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * 服務員類
 */
@Component
public class Waiter {
    /**
     * 服務
     * @param name
     */
    public String serve(String name) {
        System.out.println(name + ",您好，很高興爲您服務。");
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
        return name + ",您好，如今是北京時間" + format.format(new Date());
    }

    /**
     * 開車
     * @param name
     */
    public void driving(String name) {
        throw new RuntimeException(name + "，您好，禁止酒後駕車！");
    }
}

二、爲Waiter加強新的類 Management

package com.test.springadvicetype.introductioninterceptor;

public interface Management {
    /**
     * 管理
     * @param name
     */
    void manage(String name);
}

三、Management 的實現類，DelegatingIntroductionInterceptor已經實現了引介加強接口IntroductionInterceptor，直接繼承。

package com.test.springadvicetype.introductioninterceptor;

import org.springframework.aop.support.DelegatingIntroductionInterceptor;

/**
 * 經理類
 */
public class Manager extends DelegatingIntroductionInterceptor implements Management {

    @Override
    public void manage(String name) {
        System.out.println(name + "，您好，我是經理，負責管理服務員");
    }
}

四、xml配置，spring-chapter3-springintroductioninterceptor.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:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/aop 
http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context 
http://www.springframework.org/schema/context/spring-context.xsd">
    <!-- 開啓註解掃描 -->
    <context:component-scan base-package="com.test.springadvicetype"/>

    <bean id="waiter" class="com.test.springadvicetype.Waiter"/>

    <bean id="manager2" class="com.test.springadvicetype.introductioninterceptor.Manager"/>

    <bean id="waiterProxy" class="org.springframework.aop.framework.ProxyFactoryBean"
          p:interfaces="com.test.springadvicetype.introductioninterceptor.Management"
          p:interceptorNames="manager2"
          p:target-ref = "waiter"
          p:proxyTargetClass="true"/>
</beans>

五、測試代碼

package com.test.springadvicetype.introductioninterceptor;

import com.test.springadvicetype.Waiter;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Spring引介加強測試
 */
public class SpringIntroductionInterceptorDemo {

    public static void main(String[] args) {
        System.out.println("Spring引介加強測試");
        System.out.println("==========我是分割線==========");
        ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring-chapter3-springintroductioninterceptor.xml");
        Waiter waiterProxy = (Waiter) context.getBean("waiterProxy");
        waiterProxy.serve("Michael");
        System.out.println("==========我是分割線==========");
        Management manager = (Management)waiterProxy;
        manager.manage("Michael");
    }
}

六、運行結果

Spring環繞加強測試
==========我是分割線==========
前置加強執行了
Michael,您好，很高興爲您服務。
後置加強執行了
==========我是分割線==========
前置加強執行了
Tommy,您好，很高興爲您服務。
後置加強執行了