（转）一个简单的Spring的AOP例子

经过这段日子的学习和使用Spring,慢慢地体会到Spring的优妙之处，正在深入地吸收Spring的精华，呵呵。现在写的这个只是个简单AOP例子,包括前置通知，后置通知,环绕通知,和目标对象。写这个例子的主要目标只是想让想学AOP的能更快地入门，了解一下如何去配置AOP里面的东东。
目标对象的接口:IStudent.java

?1/**
?2?*?
?3?*/
?4package?com.dragon.study;
?5
?6/**
?7?*?@author?dragon
?8?*
?9?*/
10public?interface?IStudent?{
11????
12????public?void?addStudent(String?name);
13}
14

目标类:StudentImpl.java

?1/**
?2?*?
?3?*/
?4package?com.dragon.study.Impl;
?5
?6import?com.dragon.study.IStudent;
?7
?8/**
?9?*?@author?dragon
10?*
11?*/
12public?class?StudentImpl?implements?IStudent{
13
14?????public?void?addStudent(String?name){
15?????????System.out.println("欢迎?"+name+"?你加入Spring家庭!");
16?????}
17}
18

前置通知:BeforeAdvice.java

?1/**
?2?*?
?3?*/
?4package?com.dragon.Advice;
?5
?6import?java.lang.reflect.Method;
?7
?8import?org.springframework.aop.MethodBeforeAdvice;
?9
10/**
11?*?@author?dragon
12?*
13?*/
14public?class?BeforeAdvice?implements?MethodBeforeAdvice{
15
16??????public?void?before(Method?method,Object[]?args,?Object?target)
17???????????????throws?Throwable{
18??????????
19??????????System.out.println("这是BeforeAdvice类的before方法.");
20??????????
21??????}
22}
23

后置通知:AfterAdvice.java

?1/**
?2?*?
?3?*/
?4package?com.dragon.Advice;
?5
?6import?java.lang.reflect.Method;
?7
?8import?org.springframework.aop.AfterReturningAdvice;
?9
10/**
11?*?@author?dragon
12?*
13?*/
14public?class?AfterAdvice?implements?AfterReturningAdvice{
15????
16????public?void?afterReturning(Object?returnValue?,Method?method,
17???????????????????Object[]?args,Object?target)?throws?Throwable{
18????????System.out.println("这是AfterAdvice类的afterReturning方法.");
19????}
20??????
21
22}
23

环绕通知:CompareInterceptor.java

?1/**
?2?*?
?3?*/
?4package?com.dragon.Advice;
?5
?6import?org.aopalliance.intercept.MethodInterceptor;
?7import?org.aopalliance.intercept.MethodInvocation;
?8
?9
10/**
11?*?@author?dragon
12?*
13?*/
14public?class?CompareInterceptor?implements?MethodInterceptor{
15
16??????public?Object?invoke(MethodInvocation?invocation)?throws?Throwable{
17??????????Object?result?=?null;
18?????????String?stu_name?=?invocation.getArguments()[0].toString();
19?????????if?(?stu_name.equals("dragon")){
20?????????????//如果学生是dragon时,执行目标方法,
21??????????????result=?invocation.proceed();
22??????????????
23?????????}?else{
24?????????????System.out.println("此学生是"+stu_name+"而不是dragon,不批准其加入.");
25?????????}
26????????
27??????????return?result;
28??????}
29}
30

配置文件applicationContext.xml

?1<?xml?version="1.0"?encoding="UTF-8"?>
?2<!DOCTYPE?beans?PUBLIC?"-//SPRING//DTD?BEAN//EN"?"http://www.springframework.org/dtd/spring-beans.dtd">
?3
?4<beans>
?5
?6<bean?id="beforeAdvice"?class="com.dragon.Advice.BeforeAdvice"></bean>
?7<bean?id="afterAdvice"?class="com.dragon.Advice.AfterAdvice"></bean>
?8<bean?id="compareInterceptor"?class="com.dragon.Advice.CompareInterceptor"></bean>
?9<bean?id="studenttarget"?class="com.dragon.study.Impl.StudentImpl"></bean>
10
11<bean?id="student"?class="org.springframework.aop.framework.ProxyFactoryBean">
12??<property?name="proxyInterfaces">
13????<value>com.dragon.study.IStudent</value>
14??</property>
15??<property?name="interceptorNames">
16????<list>
17?????<value>beforeAdvice</value>
18?????<value>afterAdvice</value>
19????<value>compareInterceptor</value>??
20????</list>
21??</property>
22??<property?name="target">
23????<ref?bean="studenttarget"/>
24??</property>
25
26</bean>
27
28
29
30
31</beans>

? 现在开始写测试类,Test.java

?1/**
?2?*?
?3?*/
?4package?com;
?5
?6import?org.springframework.context.ApplicationContext;
?7import?org.springframework.context.support.FileSystemXmlApplicationContext;
?8
?9import?com.dragon.study.IStudent;
10
11/**
12?*?@author?dragon
13?*
14?*/
15public?class?Test?{
16
17????/**
18?????*?@param?args
19?????*/
20????public?static?void?main(String[]?args)?{
21????????//?TODO?Auto-generated?method?stub
22??????ApplicationContext?ctx?=?
23??????????new?FileSystemXmlApplicationContext("/com/dragon/applicationContext.xml");
24??????
25??????IStudent?person?=?(IStudent)ctx.getBean("student");
26??????person.addStudent("dragon");
27??????
28//??????person.addStudent("javadragon");
29????}
30
31}
32