Spring之AOP

之前在另外一篇博文里介绍过AOP的概念, 这边不在赘述, 可以参考 AOP与动态代理

本文主要介绍Spring中AOP的应用.

切入点: 具体实现类的方法 连接点: 接口中的方法

Advice

• 前置MethodBeforeAdvice
• 后置AfterReturnAdvice
• 环绕MethodInterceptor
• ThrowsAdvice

 1 public class MyServiceBeforeAdvice implements MethodBeforeAdvice{
 2     @Override
 3     public void before(Method method, Object[] args, Object target) throws Throwable {
 4         System.out.println("MyServiceBeforeAdvice");
 5     }
 6 }
 7 
 8 public class MyServiceAfterService implements AfterReturningAdvice{
 9     @Override
10     public void afterReturning(Object returnValue, Method method, Object[] args, Object target) throws Throwable {
11         System.out.println("MyServiceAfterService");
12     }
13 }
14 
15 
16 public class MyMethodInterceptor implements MethodInterceptor{
17     @Override
18     public Object invoke(MethodInvocation invocation) throws Throwable {
19         System.out.println("before");
20         Object result = invocation.proceed();
21         System.out.println("after");
22         return result;
23     }
24 }

对应的xml写法

 1         <bean id="someService" class="day1207.ServiceImpl"/>
 2 
 3         <bean id="myAdvice" class="day1207.MyServiceBeforeAdvice"/>
 4         <bean id="myAdvice2" class="day1207.MyServiceAfterService"/>
 5         <bean id="myAdvice3" class="day1207.MyMethodInterceptor"/>
 6 
 7         <bean id="serviceProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
 8                 <property name="target" ref="someService"/>
 9                 <property name="interceptorNames" value="myAdvice, myAdvice2, myAdvice3"/>
10         </bean>

 CGlib代理

 Spring中默认有接口的对象直接用的jdk动态代理实现的AOP, 无接口的对象用CGlib实现的.

如果想要强制都用CGlib实现, 则可以通过以下配置

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

 或者

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

Advisor

PointcutAdvisor: 可以指定具体切入点位置.

NameMatchMethodPointcutAdvisor 名称匹配

1         <bean id="myAdvisor" class="org.springframework.aop.support.NameMatchMethodPointcutAdvisor">
2                 <property name="advice" ref="myAdvice2"/>
3                 <!-- 匹配对象是简单方法名 -->
4                 <property name="mappedNames" value="doFirst, doSecond"/>
5         </bean>

RegexpMethodPointcutAdvisor 正则匹配

1         <bean id="myAdvisor" class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
2                 <property name="advice" ref="myAdvice2"/>
3                 <!--匹配全限定性方法路径-->
4                 <property name="pattern" value=".*S.*"/>
5         </bean>

自动代理生成器

用于解决多个Bean需要对应多个代理的问题.

Advisor代理生成器

1         <bean class="org.springframework.aop.framework.autoproxy.DefaultAdvisorAutoProxyCreator"/>

缺点: 范围太广, 无法指定差异化Bean处理, 不能选择切面类型, 只能Advisor. 内部实现是用的BeanPostProcessor.

Bean名称自动代理生成器

1         <bean class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
2                 <property name="beanNames" value="someService"/>
3                 <property name="interceptorNames" value="myAdvisor"/>
4         </bean>