Spring的AOP(面向切面编程)

[code]<?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:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.2.xsd">

<!-- 通过bean元素声明需要创建的对象实例,该实例的class属性表示类型,id属性表示表示该实例的名称(必须唯一) -->
<!-- 创建实例 -->
<bean id="student" class="com.pojo.Student">
<!--property元素用来为实例属性赋值,这里调用的set方法赋值 name="属性名" value="属性值" -->
<property name="stuName" value="张三"></property>
</bean>

<!-- 定义切面的bean -->
<bean id="stuLogger" class="com.pojo.StuLogger"></bean>

<!-- aop的增强处理 -->
<aop:config>
<!-- 定义切点expression="execution(需要增强的方法)" id="切点的名称" -->
<aop:pointcut expression="execution(* com.pojo.*.*(..))" id="pt"></aop:pointcut>
<!-- 各种增强 ref="引入切面的bean" -->
<aop:aspect ref="stuLogger">
<!-- 前置增强 method="实例中增强的方法名" pointcut-ref="引入需要增强的切点" -->
<aop:before method="before" pointcut-ref="pt" />
<!-- 后置增强 -->
<aop:after method="after" pointcut-ref="pt" />
<!-- 返回增强 returning="返回值"-->
<aop:before-returning method="returning" returning="res" pointcut-ref="pt" />
<!-- 异常增强 throwing="返回值" -->
<aop:before-throwing method="throwing" throwing="e" pointcut-ref="pt" />
<!-- 环绕增强 -->
<aop:around method="around" pointcut-ref="pt" />
</aop:aspect>
</aop:config>
</beans>

[code]<?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:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.2.xsd">

<!-- 扫描包中注解标注的类,可以写多个包,用逗号隔开-->
<context:component-scan base-package="com.pojo"></context:component-scan>
<!-- 启动对@AspectJ注解的支持 -->
<aop:aspectj-autoproxy></aop:aspectj-autoproxy>
</beans>

[code]package com.pojo;

import org.springframework.stereotype.Component;

//使用注解定义了一个bean 相当于xml配置文件中<bean id="student" class="com.pojo.Student"></bean>
@Component("student")
public class Student {

public void study(){
System.out.println("学生正在学习");
}

public String work(){
return "这是返回值";
}

public void exce(){
throw new RuntimeException("出现异常了");
}
}

[code]package com.pojo;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;

//使用注解定义切面
@Component
@Aspect
public class StuLogger {

//单独定义一个切入点可以共用
@Pointcut("execution(public void study())")
public void aa(){

}

//前置增强
@Before("aa()")
public void before(JoinPoint jp){
System.out.println("目标对象:"+jp.getTarget()+",方法:"+jp.getSignature().getName()+"--进行前置增强-----");
}
//后置增强
@After("aa()")
public void after(JoinPoint jp){
System.out.println("目标对象:"+jp.getTarget()+",方法:"+jp.getSignature().getName()+"--进行后置增强-----");
}
//返回增强
@AfterReturning(value="execution(public String work())",returning="res")
public void returning(JoinPoint jp,Object res){
System.out.println("目标对象:"+jp.getTarget()+",方法:"+jp.getSignature().getName()+"--进行返回增强-----返回值是:"+res);
}
//异常增强
@AfterThrowing(value="execution(public void exce())",throwing="e")
public void throwing(JoinPoint jp,Exception e){
System.out.println("目标对象:"+jp.getTarget()+",方法:"+jp.getSignature().getName()+"--进行异常增强-----异常:"+e);
}
}

[code]package com.test;

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

import com.pojo.Student;

public class SpringAopTest {
public static void main(String[] args) {
ApplicationContext	ctx=new ClassPathXmlApplicationContext("applicationContext.xml");
Student s1 =(Student) ctx.getBean("student");
s1.study();//根据..调方法
}
}