Spring中基于xml的AOP

在Spring中，我们可以通过AOP标签来定义切面、切入点和通知。

所有aop标签如下：

<aop:config>                                       aop定义开始（有序）

<aop:pointcut/>                                  切入点定义

<aop:advisor/>                                    通知定义

<aop:aspect>                                       切面定义开始（内部无序）

<aop:pointcut/>                                    切入点定义

<aop:before/>                                       前置通知定义

<aop:after-returning/>                          后置返回通知定义

<aop:after-throwing/>                           后置异常通知定义

<aop:after/>                                             后置最终通知定义

<aop:around/>                                        环绕通知定义

<aop:declare-parents/>                         引入定义

</aop:aspect>

</aop:config>

1.前置通知实例

调用类

package cn.belle.test;public class HelloWorldService {public void sayBefore(String param) {      System.out.println("我是前置通知");  }  }

切面类

package cn.belle.test;public class HelloAspect {public void beforeAdvice(String param) {System.out.println("我是前置通知的通知方法"+param);}}

Spring配置文件

<?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:aop="http://www.springframework.org/schema/aop"xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd"><bean id="helloWorldService" class="cn.belle.test.HelloWorldService"/><bean id="aspect" class="cn.belle.test.HelloAspect" /><aop:config>    <aop:aspect ref="aspect">        <aop:before method="beforeAdvice(java.lang.String)" arg-names="param" pointcut="execution(* cn.belle..*.sayBefore(..)) and args(param)" />    </aop:aspect></aop:config></beans>

pointcut :切入点；method :切面内通知方法 ; arg-names:切面类通知方法的参数名字（这里参数是与调用类同名的参数）
测试类

public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");   HelloWorldService helloworldService = ctx.getBean("helloWorldService", HelloWorldService.class);       helloworldService.sayBefore("before");}

2.后置最终通知

调用类

package cn.belle.test;public class HelloWorldService {public void sayAfterFinally() {System.out.println("我是后置最终通知");}}

切面类

package cn.belle.test;public class HelloAspect {public void afterFinallyAdvice() {        System.out.println("我是后置最终通知的通知方法");}}

配置文件

<bean id="helloWorldService" class="cn.belle.test.HelloWorldService"/><bean id="aspect" class="cn.belle.test.HelloAspect" /><aop:config>    <aop:aspect ref="aspect">        <aop:after pointcut="execution(* cn.belle..*.sayAfterFinally(..))" method="afterFinallyAdvice"/>     </aop:aspect></aop:config>

测试类

public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");   HelloWorldService helloworldService = ctx.getBean("helloWorldService", HelloWorldService.class);       helloworldService.sayAfterFinally();}

3.后置返回通知

调用类

package cn.belle.test;public class HelloWorldService {public boolean sayAfterReturning() {System.out.println("我是后置返回通知");return true;}}

切面类

package cn.belle.test;public class HelloAspect {public void afterReturningAdvice(Object retVal) {        System.out.println("我是后置返回通知的通知方法"+retVal);}}

配置文件

<bean id="helloWorldService" class="cn.belle.test.HelloWorldService"/><bean id="aspect" class="cn.belle.test.HelloAspect" /><aop:config>    <aop:aspect ref="aspect">        <aop:after-returning pointcut="execution(* cn.belle..*.sayAfterReturning(..))" method="afterReturningAdvice" arg-names="retVal" returning="retVal" />     </aop:aspect></aop:config>

returning 指的是调用类返回值

测试类

public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");   HelloWorldService helloworldService = ctx.getBean("helloWorldService", HelloWorldService.class);       helloworldService.sayAfterReturning();}

4.后置异常通知

调用类

package cn.belle.test;public class HelloWorldService {public void sayAfterThrowing() {System.out.println("我是后置异常通知");throw new RuntimeException();}}

切面类

package cn.belle.test;public class HelloAspect {public void afterThrowingAdvice(Exception exception) {        System.out.println("我是后置异常通知的通知方法"+exception);}}

配置文件

<bean id="helloWorldService" class="cn.belle.test.HelloWorldService"/><bean id="aspect" class="cn.belle.test.HelloAspect" /><aop:config>    <aop:aspect ref="aspect">        <aop:after-throwing pointcut="execution(* cn.belle..*.sayAfterThrowing(..))" method="afterThrowingAdvice" arg-names="exception" throwing="exception" />     </aop:aspect></aop:config>

测试类

ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");   HelloWorldService helloworldService = ctx.getBean("helloWorldService", HelloWorldService.class);       helloworldService.sayAfterThrowing();

5.环绕通知

调用类

package cn.belle.test;public class HelloWorldService {public void sayAround(String param) {System.out.println("我是环绕通知"+ param);}}

切面类

package cn.belle.test;import org.aspectj.lang.ProceedingJoinPoint;public class HelloAspect {public Object aroundAdvice(ProceedingJoinPoint pjp) throws Throwable {Object retVal = pjp.proceed(new Object[] { "replace" });System.out.println("环绕通知的通知方法");return retVal;}}

配置文件

<bean id="helloWorldService" class="cn.belle.test.HelloWorldService"/><bean id="aspect" class="cn.belle.test.HelloAspect" /><aop:config>    <aop:aspect ref="aspect">        <aop:around pointcut="execution(* cn.belle..*.sayAround(..))" method="aroundAdvice"  />     </aop:aspect></aop:config>

测试类

 ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");   HelloWorldService helloworldService = ctx.getBean("helloWorldService", HelloWorldService.class);       helloworldService.sayAround("Around");