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 )