spring aop小例子

接口类：

package com.test.TestSpring3;   

public interface UserService // 被拦截的接口   
{   
    public void printUser(String user);   
}   

实现类：

package com.test.TestSpring3;   

public class UserServiceImp implements UserService // 实现UserService接口   
{   
    public void printUser(String user) ...{   
        System.out.println("printUser user:" + user);// 显示user   
    }   
}   

AOP拦截器

package com.test.TestSpring3;   

import org.aopalliance.intercept.MethodInterceptor;   
import org.aopalliance.intercept.MethodInvocation;   

public class UserInterceptor implements MethodInterceptor   
// AOP方法拦截器   
{   

    public Object invoke(MethodInvocation arg0) throws Throwable ...{   

        try {   

            if (arg0.getMethod().getName().equals("printUser"))   
            // 拦截方法是否是UserService接口的printUser方法   
            {   
                Object[] args = arg0.getArguments();// 被拦截的参数   
                System.out.println("user:" + args[0]);   
                arg0.getArguments()[0] = "hello!";// 修改被拦截的参数   

            }   

            System.out.println(arg0.getMethod().getName() + "---!");   
            return arg0.proceed();// 运行UserService接口的printUser方法   

        } catch (Exception e) {   
            throw e;   
        }   
    }   
}   

测试类

package com.test.TestSpring3;   

import org.springframework.beans.factory.BeanFactory;   

import org.springframework.beans.factory.xml.XmlBeanFactory;   
import org.springframework.context.ApplicationContext;   
import org.springframework.context.support.ClassPathXmlApplicationContext;   
import org.springframework.context.support.FileSystemXmlApplicationContext;   
import org.springframework.core.io.ClassPathResource;   
import org.springframework.core.io.Resource;   
import org.springframework.web.context.support.WebApplicationContextUtils;   

public class TestInterceptor {   

    public static void main(String[] args) {   
        ApplicationContext ctx = new FileSystemXmlApplicationContext(   
                "classpath:applicationContext.xml");   
//        ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");       

        UserService us = (UserService) ctx.getBean("userService");   
        us.printUser("shawn");   

    }   
}

配置文件

<?xml version="1.0" encoding="UTF-8"?>  
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">  
<beans>  
    <bean id="userServiceImp"  
        class="com.test.TestSpring3.UserServiceImp" />  

    <bean id="userInterceptor" class="com.test.TestSpring3.UserInterceptor" />  

    <bean id="userService"  
        class="org.springframework.aop.framework.ProxyFactoryBean">  
      <!-- 代理接口 -->  
        <property name="proxyInterfaces">  
            <value>com.test.TestSpring3.UserService</value>  
        </property>  
       <!-- 目标实现类 -->  
        <property name="target">  
            <ref local="userServiceImp" />    
      </property>  
        <!-- 拦截器 -->  
        <property name="interceptorNames">  
            <list>  
                <value>userInterceptor</value>  
            </list>  
        </property>  
    </bean>  

</beans>  

输出:
user:shawn
printUser---!
printUser user:hello!