一个简单的Spring的AOP的例子

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

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/**

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*

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*/

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package com.dragon.study;

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/**

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* @author dragon

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*

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*/

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public interface IStudent {

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public void addStudent(String name);

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}

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目标类:StudentImpl.java

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/**

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*

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*/

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package com.dragon.study.Impl;

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import com.dragon.study.IStudent;

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/**

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* @author dragon

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*

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*/

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public class StudentImpl implements IStudent {

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public void addStudent(String name) {

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System.out.println( " 欢迎 " + name + " 你加入Spring家庭! " );

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}

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}

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前置通知:BeforeAdvice.java

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/**

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*

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*/

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package com.dragon.Advice;

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import java.lang.reflect.Method;

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import org.springframework.aop.MethodBeforeAdvice;

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/**

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* @author dragon

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*

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*/

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public class BeforeAdvice implements MethodBeforeAdvice {

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public void before(Method method,Object[] args, Object target)

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throws Throwable {

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System.out.println( " 这是BeforeAdvice类的before方法. " );

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}

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}

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后置通知:AfterAdvice.java

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/**

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*

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*/

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package com.dragon.Advice;

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import java.lang.reflect.Method;

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import org.springframework.aop.AfterReturningAdvice;

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/**

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* @author dragon

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*

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*/

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public class AfterAdvice implements AfterReturningAdvice{

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public void afterReturning(Object returnValue ,Method method,

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Object[] args,Object target) throws Throwable{

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System.out.println("这是AfterAdvice类的afterReturning方法.");

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}

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}

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环绕通知:CompareInterceptor.java

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/**

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*

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*/

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package com.dragon.Advice;

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import org.aopalliance.intercept.MethodInterceptor;

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import org.aopalliance.intercept.MethodInvocation;

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/**

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* @author dragon

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*

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*/

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public class CompareInterceptor implements MethodInterceptor{

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public Object invoke(MethodInvocation invocation) throws Throwable{

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Object result = null;

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String stu_name = invocation.getArguments()[0].toString();

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if ( stu_name.equals("dragon")){

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//如果学生是dragon时,执行目标方法,

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result= invocation.proceed();

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} else{

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System.out.println("此学生是"+stu_name+"而不是dragon,不批准其加入.");

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}

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return result;

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}

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}

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配置文件applicationContext.xml

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<?xml version="1.0" encoding="UTF-8"?>

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<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">

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<beans>

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<bean id="beforeAdvice" class="com.dragon.Advice.BeforeAdvice"></bean>

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<bean id="afterAdvice" class="com.dragon.Advice.AfterAdvice"></bean>

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<bean id="compareInterceptor" class="com.dragon.Advice.CompareInterceptor"></bean>

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<bean id="studenttarget" class="com.dragon.study.Impl.StudentImpl"></bean>

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<bean id="student" class="org.springframework.aop.framework.ProxyFactoryBean">

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<property name="proxyInterfaces">

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<value>com.dragon.study.IStudent</value>

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</property>

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<property name="interceptorNames">

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<list>

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<value>beforeAdvice</value>

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<value>afterAdvice</value>

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<value>compareInterceptor</value>

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</list>

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</property>

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<property name="target">

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<ref bean="studenttarget"/>

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</property>

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</bean>

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</beans>

现在开始写测试类,Test.java

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/**

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*

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*/

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package com;

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import org.springframework.context.ApplicationContext;

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import org.springframework.context.support.FileSystemXmlApplicationContext;

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import com.dragon.study.IStudent;

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/**

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* @author dragon

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*

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*/

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public class Test {

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/**

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* @param args

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*/

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public static void main(String[] args) {

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// TODO Auto-generated method stub

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ApplicationContext ctx =

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new FileSystemXmlApplicationContext("/com/dragon/applicationContext.xml");

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IStudent person = (IStudent)ctx.getBean("student");

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person.addStudent("dragon");

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// person.addStudent("javadragon");

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}

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}

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