一个简单的spring AOP例子

转自:http://meiowei.iteye.com/blog/413919

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*/
4packagecom.dragon.study;
5
6/**
7*@authordragon
8*
9*/
10publicinterfaceIStudent{
11
12publicvoidaddStudent(Stringname);
13}

目标类:StudentImpl.java

1/**
2*
3*/
4packagecom.dragon.study.Impl;
5
6importcom.dragon.study.IStudent;
7
8/**
9*@authordragon
10*
11*/
12publicclassStudentImplimplementsIStudent{
13
14publicvoidaddStudent(Stringname){
15System.out.println("欢迎"+name+"你加入Spring家庭!");
16}
17}
18

前置通知:BeforeAdvice.java

1/**
2*
3*/
4packagecom.dragon.Advice;
5
6importjava.lang.reflect.Method;
7
8importorg.springframework.aop.MethodBeforeAdvice;
9
10/**
11*@authordragon
12*
13*/
14publicclassBeforeAdviceimplementsMethodBeforeAdvice{
15
16publicvoidbefore(Methodmethod,Object[]args,Objecttarget)
17throwsThrowable{
18
19System.out.println("这是BeforeAdvice类的before方法.");
20
21}
22}

后置通知:AfterAdvice.java

1/**
2*
3*/
4packagecom.dragon.Advice;
5
6importjava.lang.reflect.Method;
7
8importorg.springframework.aop.AfterReturningAdvice;
9
10/**
11*@authordragon
12*
13*/
14publicclassAfterAdviceimplementsAfterReturningAdvice{
15
16publicvoidafterReturning(ObjectreturnValue,Methodmethod,
17Object[]args,Objecttarget)throwsThrowable{
18System.out.println("这是AfterAdvice类的afterReturning方法.");
19}
20
21
22}

环绕通知:CompareInterceptor.java

1/**
2*
3*/
4packagecom.dragon.Advice;
5
6importorg.aopalliance.intercept.MethodInterceptor;
7importorg.aopalliance.intercept.MethodInvocation;
8
9
10/**
11*@authordragon
12*
13*/
14publicclassCompareInterceptorimplementsMethodInterceptor{
15
16publicObjectinvoke(MethodInvocationinvocation)throwsThrowable{
17Objectresult=null;
18Stringstu_name=invocation.getArguments()[0].toString();
19if(stu_name.equals("dragon")){
20//如果学生是dragon时,执行目标方法,
21result=invocation.proceed();
22
23}else{
24System.out.println("此学生是"+stu_name+"而不是dragon,不批准其加入.");
25}
26
27returnresult;
28}
29}

配置文件applicationContext.xml

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

现在开始写测试类,Test.java

1/**
2*
3*/
4packagecom;
5
6importorg.springframework.context.ApplicationContext;
7importorg.springframework.context.support.FileSystemXmlApplicationContext;
8
9importcom.dragon.study.IStudent;
10
11/**
12*@authordragon
13*
14*/
15publicclassTest{
16
17/**
18*@paramargs
19*/
20publicstaticvoidmain(String[]args){
21//TODOAuto-generatedmethodstub
22ApplicationContextctx=
23newFileSystemXmlApplicationContext("/com/dragon/applicationContext.xml");
24
25IStudentperson=(IStudent)ctx.getBean("student");
26person.addStudent("dragon");
27
28//person.addStudent("javadragon");
29}
30
31}
32

当然，运行该程序时，要加上commons-logging.jar 包

在Spring Appactiocontext.xml配置文件；你定义的前置，后置；环绕等通知在配置文件中实现了代理（org.springframework.aop.framework.ProxyFactoryBean）
以此将通知放入到了原Bean中；这样才能使原Bean中方法调用时自动执行通知
这是其一》
<property name="proxyInterfaces">
<property name="interceptorNames">
<property name="target">
这三个属性是一定要配置的
第一是被代理的接口（IStudent）
第二是通知列表（前置，后置；环绕）上面定义的三个类
第三是被代理的原Bean(StudentImpl )