AOP 切面编程学习笔记

介绍：  aop.aspect这个包里面放的是切面类，这是一个关注点（共同业务）的模块化，这个关注点可能会横切多个对象

　　　　aop.service这个包里面放的是被切面横切的目标，EmpService  Deptservice

　　　　aop-beans是配置文件，里面有bean的配置，切入点（切入点里面有一个表达式，可以判断哪些方法需要切入）的配置，通知（判断切入到哪里,执行什么方法）等。

 

package aop.aspect;

public class Myaspect {
    public void afterReturn(Object retVal){
        if(retVal==null){
            retVal="";
        }
        System.out.println("aspect's afterReturn execute"+"  "+retVal);
    }
    
    public void before(){
        System.out.println("aspect's before execute");
    }

}

 

package aop.service;

public class DeptServiceImpl implements DeptService {

    public boolean save() {
        // TODO Auto-generated method stub
        System.out.println("DeptServiceImpl's save execute");
        return true;
    }

    public void update() {
        // TODO Auto-generated method stub

    }

}

 

package aop.service;

public class EmpServiceImpl implements EmpService {

    @Override
    public void delete() {
        // TODO Auto-generated method stub
        System.out.println("EmpServiceImpl's delete execute");
    }

}

 

<?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"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
                http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
                http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">
                <bean  id="deptService" class="aop.service.DeptServiceImpl" scope="prototype"></bean>
                <bean id="empService" class="aop.service.EmpServiceImpl" scope="prototype"></bean>
                <bean id="myaspect" class="aop.aspect.Myaspect"></bean>
                <aop:config>
                    <aop:aspect id="aspect" ref="myaspect">
                        <aop:pointcut id="myPointCut" expression="execution (* aop.service.*.* (..))"></aop:pointcut>
                        <!-- 定义前置通知 -->
                        <aop:before pointcut-ref="myPointCut" method="before"></aop:before>
                        <!-- 定义最终通知 -->
                        <aop:after pointcut-ref="myPointCut" method="before"></aop:after>
                        <aop:after-returning  pointcut-ref="myPointCut" method="afterReturn"  returning="retVal"></aop:after-returning>
                    </aop:aspect>
                </aop:config>
                
                
                </beans>

 

package test;

import he.bean.PersonAction;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import aop.service.DeptService;
import aop.service.DeptServiceImpl;
import aop.service.EmpService;


public class TestAll {
    
    @Test
    public void testPersonAction(){
        AbstractApplicationContext ac = new ClassPathXmlApplicationContext("aop-beans.xml");
        DeptService deptService =   (DeptService) ac.getBean("deptService");
        deptService.save();
        //EmpService empService =   (EmpService) ac.getBean("empService");
        //empService.delete();
    }

}