<七>AOP面向切面——配置bean.xml文件方式声明切面(附源码)

上一节为注解方式声明切面，现在通过配置bean.xml文件的形式来配置。

1、将上面的MyInterceptor变成一个普通的java类，即去掉@Aspect这样的注解。并将参数去掉。

package cn.itcast.service;

import org.aspectj.lang.ProceedingJoinPoint;

/**
* 切面
*
*/

public class MyInterceptor {

public void doAccessCheck() {
System.out.println("前置通知:");
}

public void doAfterReturning()
{
System.out.println("后置通知");
}

public void doAfter(){
System.out.println("最终通知");
}

public void doAfterThrowing(){
System.out.println("例外通知");
}

public Object doBasicProfilling(ProceedingJoinPoint pjp) throws Throwable{
System.out.println("进入方法");
Object result=pjp.proceed();
System.out.println("退出方法");
return result;
}
}

2、beans.xml文件

<?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"> <aop:aspectj-autoproxy/>
<bean id="personService" class="cn.itcast.service.impl.PersonServiceBean"/>
<bean id="aspectbean" class="cn.itcast.service.MyInterceptor"/>
<aop:config>
<aop:aspect id="asp" ref="aspectbean">
<aop:pointcut id="mycut"
expression="execution(* cn.itcast.service.impl.PersonServiceBean.*(..))" />
<aop:before pointcut-ref="mycut" method="doAccessCheck" />
<aop:after-returning pointcut-ref="mycut" method="doAfterReturning"/>
<aop:after-throwing pointcut-ref="mycut" method="doAfterThrowing"/>
<aop:after pointcut-ref="mycut" method="doAfter"/>
<aop:around pointcut-ref="mycut" method="doBasicProfilling"/>
</aop:aspect>
</aop:config>
</beans>

说明：

<aop:pointcut id="mycut" expression="execution(java.lang.String cn.itcast.service.impl.PersonServiceBean.*(..))" />
将会只拦截cn.itcast.service.impl.PersonServiceBean类中的返回值为string类型的方法

<aop:pointcut id="mycut" expression="execution(* cn.itcast.service.impl.PersonServiceBean.*(java.lang.String,..))" />
将会只拦截cn.itcast.service.impl.PersonServiceBean类中的参数有string类型的方法

<aop:pointcut id="mycut" expression="execution(!void cn.itcast.service.impl.PersonServiceBean.*(..))" />
将会只拦截cn.itcast.service.impl.PersonServiceBean类中的返回值不为空的方法

spring发现前面定义的切口的类有实现接口，则用jdk的创建代理技术进行创建代理对象；
如果没有实现接口，则用CGlib来创建代理对象

3、测试SpringAOPTest.java

package junit.test;

import org.junit.BeforeClass;
import org.junit.Test;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import cn.itcast.service.PersonService;

public class SpringAOPTest {

@BeforeClass
public static void setUpBeforeClass() throws Exception {
}

@Test public void interceptorTest(){
ApplicationContext cxt = new ClassPathXmlApplicationContext("beans.xml");
PersonService personService = (PersonService)cxt.getBean("personService");
personService.save("chen");
personService.getPersonName(3);
//personService.update("ning", 4);
}
}

完成。

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