achieve aop through xml

The main way to achive AOP is deploying a xml file。

Now a xml file is presented to be a explanation .

<?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">
	<context:annotation-config />
	<context:component-scan base-package="com.bjsxt"/>
 	<bean id="logInterceptor" class ="com.bjsxt.aop.LogInterceptor"></bean>
 	<aop:config>
 	    <aop:pointcut 
 	    expression="execution(public * com.bjsxt.service..*.add(..))" 
 	    id="servicePointcut"/>
 	    
 	    <aop:aspect id="logAspect" ref="logInterceptor">
	       <aop:before method="before" pointcut-ref="servicePointcut" />
	    </aop:aspect>
 	</aop:config>
 	
	
 

</beans>

The tag <aop:config> declares that we will deploy a aop now. 

While , I declare a "pointcut" at first.  It is obvious that it's a globe pointcut and it works for every aspect behind it . 

"expression="execution(public * com.bjsxt.service..*.add(..))" shows the pointcut represent all method like “add（）” in the classes of  the package named"com.bjsxt.service.."

the pointcut‘s id is “servicePointcut” in addition。

Next， a aspect is declared whose name is “logAspect” 。 （nobody care what name it has in this situation）。

 pointcut-ref="servicePointcut" shows that it is a aspect for the pointcut named “servicePointcut”which we had created a moment ago.

 Its ref =  <span style="font-family: Arial, Helvetica, sans-serif;">"logInterceptor" ，so we can find a bean named logInterceptor  to know what methods the aspect has。And according to the sentence “<aop:before method</span>

<span style="font-family: Arial, Helvetica, sans-serif;">="before"  " , I think we must do the method named "before" in "logIntercepor "  as the type of" before method". It means the method woulb be done before pointcut.</span>

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<span style="font-family: Arial, Helvetica, sans-serif;">We can also complete the xml file in design mode。 It looks much more clear.</span>

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