AOP的半自动代理及缺点

AOP的通知类型:

aop联盟定义 aop通知类型，spring 对 aop联盟规范支持。

aop联盟定义5种通知

前置通知 org.springframework.aop.MethodBeforeAdvice

在目标方法执行前实施增强

后置通知 org.springframework.aop.AfterReturningAdvice

在目标方法执行后实施增强

环绕通知 org.aopalliance.intercept.MethodInterceptor

在目标方法执行前后实施增强

异常抛出通知 org.springframework.aop.ThrowsAdvice

在方法抛出异常后实施增强

引介通知 org.springframework.aop.IntroductionInterceptor（了解）对一个类进行增强（添加方法或属性等）

在目标类中添加一些新的方法和属性

如果使用aop联盟规范进行aop开发，所有的通知必须实现接口。（底层为了确定通知方法名称）

AOP的半自动代理(不带有切入点的切面---所有方法)

1.切面类

需要总结:

需要根据AOP联盟确定一个通知类型:这里使用环绕通知(环绕通知需要手动开启方法)

所以切面类随便写,随便实现一个通知类型,重写里面的invok方法在,通过参数调用

proceed()执行目标类,前后可以写代码

package com.mickeymouse.proxy;

import org.aopalliance.intercept.MethodInterceptor;

import org.aopalliance.intercept.MethodInvocation;

/**

* 切面类:包含两个通知(增强)

环绕通知必须手动执行方法

* @author Mickey-Mouse

*

*/

public class MyAspect implements MethodInterceptor {

public Object invoke(MethodInvocation mi) throws Throwable {

System.out.println( "已校验是否符合身份" );

//环绕通知必须手动执行方法

Object object = mi.proceed();

System.out.println( "方法已经执行完--->后处理" );

return object;

}

2.目标类(已实现接口)

package com.mickeymouse.proxy;

public class ProductsServiceImpl implements ProductsService {

/**

* 目标类:

* 里面有两个连接点

*/

public void addProducts(){

System.out.println( "添加商品成功" );

}

public void updateProducts(){

System.out.println( "修改商品成功" );

}

3.半自动代理XML配置

与AOP的自动代理的区别在于:

半自动代理没有使用AOP约束,要手动配置代理类与目标类的关系

半自动代理是基于ProxyFactoryBean的代理类:

缺点:

* 配置麻烦:

* 需要为每一个要增强的类配置一个ProxyFactoryBean.(只要有增强,就需要写一个ProxyFactoryBean的配置)

<? 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"

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">

< bean id = "myAspect" class = "com.mickeymouse.proxy.MyAspect" />

< bean id = "productsService" class = "com.mickeymouse.proxy.ProductsServiceImpl" />

< bean id = "proxyFactoryBean" class = "org.springframework.aop.framework.ProxyFactoryBean" >

< property name = "target" ref = "productsService" ></ property >

< property name = "interceptorNames" value = "myAspect" ></ property >

<!-- 设置切面类需要连接的接口(optimize与接口二选一即可,Spring可以自动识别,接口就动态代理,没有就CGLIB) -->

< property name = "proxyInterfaces" value = "com.mickeymouse.proxy.ProductsService" ></ property >

< property name = "optimize" value = "true" ></ property >

</ bean >

</ beans >

测试类:

@Test

public void test1(){

ApplicationContext applicationContext = new ClassPathXmlApplicationContext( "applicationContext.xml" );

ProductsService bean = applicationContext.getBean( "proxyFactoryBean" ,ProductsService. class );

bean.addProducts();

bean.updateProducts();

}

结果:

AOP的半自动代理:(配置带有切入点的切面---->个别方法)(了解)

配置文件:(其他部分是一样的 , 同上)

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

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

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

xsi:schemaLocation="

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

< bean id = "customerDao" class = "com.itheima.spring.demo4.CustomerDao" />

< bean id = "myAroundAdvice" class = "com.itheima.spring.demo4.MyAroundAdvice" />

< bean id = "myAdvisor" class = "org.springframework.aop.support.RegexpMethodPointcutAdvisor" >

<!--         <property name="patterns" value="com\.itheima\.spring\.demo4\.CustomerDao\.update,com\.itheima\.spring\.demo4\.Cus            tomerDao\.delete"/> -->

< property name = "patterns" value = ".*save.*,.*update.*" />

< property name = "advice" ref = "myAroundAdvice" />

</ bean >

< bean id = "proxyFactoryBean" class = "org.springframework.aop.framework.ProxyFactoryBean" >

< property name = "target" ref = "customerDao" />

< property name = "proxyTargetClass" value = "true" />

< property name = "interceptorNames" value = "myAdvisor" />

</ bean >

</ beans >

转载于:https://my.oschina.net/mickeymouse/blog/519118