AOP用法实践

落日映苍穹つ 2022-06-09 03:07 62阅读 0赞

一、aop的配置

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
    	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:jee="http://www.springframework.org/schema/jee"
    	xmlns:aop="http://www.springframework.org/schema/aop"
    	xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"
    	xsi:schemaLocation="http://www.springframework.org/schema/beans 
    		http://www.springframework.org/schema/beans/spring-beans-3.1.xsd 
    		http://www.springframework.org/schema/tx 
    		http://www.springframework.org/schema/tx/spring-tx-3.1.xsd 
    		http://www.springframework.org/schema/jee 
    		http://www.springframework.org/schema/jee/spring-jee-3.1.xsd 
    		http://www.springframework.org/schema/context 
    		http://www.springframework.org/schema/context/spring-context-3.1.xsd 
    		http://www.springframework.org/schema/aop 
    		http://www.springframework.org/schema/aop/spring-aop-3.1.xsd">
                
    	<bean id="aopExampleImpl1" class="com.terisadeng.spring.aop.AopExampleImpl1"></bean>  
    	<bean id="aopExampleImpl2" class="com.terisadeng.spring.aop.AopExampleImpl2"></bean>   
    	<bean id="timeLogger" class="com.terisadeng.spring.aop.TimeLogger"></bean>   
    	
    	<aop:config proxy-target-class="true">
    		<aop:aspect id="time" ref="timeLogger">
    			<aop:pointcut id="AllMethod" expression="execution(* com.terisadeng.spring.aop.AopExample.*(..))"></aop:pointcut>
    			<aop:before method="costTime" pointcut-ref="AllMethod"></aop:before>
    			<aop:after method="costTime" pointcut-ref="AllMethod"></aop:after>
    		</aop:aspect>
    		
    	</aop:config>    
    </beans>

二、创建一个目标接口及两个实现类

package com.terisadeng.spring.aop;
    
    public interface AopExample
    {
        void enterAopExample();
        void outAopExample();
    }
    
    package com.terisadeng.spring.aop;
    
    public class AopExampleImpl1 implements AopExample
    {
    
    		//该方法作为切入点
        @Override
        public void enterAopExample()
        {
            System.out.println("Enter AopExampleImpl1.enterAopExample()");
        }
    
    		//该方法作为切入点
        @Override
        public void outAopExample()
        {
            System.out.println("Enter AopExampleImpl1.outAopExample()");
        }
    
    }
    
    package com.terisadeng.spring.aop;
    
    public class AopExampleImpl2 implements AopExample
    {
    
    		//该方法作为切入点
        @Override
        public void enterAopExample()
        {
            System.out.println("Enter AopExampleImpl2.enterAopExample()");
        }
    
    		//该方法作为切入点
        @Override
        public void outAopExample()
        {
            System.out.println("Enter AopExampleImpl2.outAopExample()");
        }
    
    }

该类是拦截到方法后进行的处理

package com.terisadeng.spring.aop;
    
    import java.text.SimpleDateFormat;
    import java.util.Date;
    
    public class TimeLogger
    {
        public void costTime(){
            Date date=new Date();
            SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:S");
            System.out.println("CurrentTime = " +sdf.format(date));
        }
    }

三、测试方法：  
1、使用Junit进行测试

package com.terisadeng.spring.aop;
    
    import javax.annotation.Resource;
    
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.test.context.ContextConfiguration;
    import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
    
    @RunWith(SpringJUnit4ClassRunner.class)
    @ContextConfiguration("classpath:aop.xml")
    public class TestAop
    {
        @Resource
        private AopExampleImpl1 aopExampleImpl1;
        
        @Resource
        private AopExampleImpl2 aopExampleImpl2;
        @Test
        public void test(){
            aopExampleImpl1.enterAopExample();
            System.out.println();
            aopExampleImpl1.outAopExample();
            System.out.println();
            aopExampleImpl2.enterAopExample();
            System.out.println();
            aopExampleImpl2.outAopExample();
        }
        
    }

2、使用慢main函数进行测试

package com.terisadeng.spring.aop;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    public class AopDemo
    {
        public static void main(String[] args)
        {
            ApplicationContext ctx=new ClassPathXmlApplicationContext("aop.xml");
            AopExampleImpl1 aopExampleImpl1=(AopExampleImpl1)ctx.getBean("aopExampleImpl1");
            AopExampleImpl2 aopExampleImpl2=(AopExampleImpl2)ctx.getBean("aopExampleImpl2");
            
            aopExampleImpl1.enterAopExample();
            System.out.println();
            aopExampleImpl1.outAopExample();
            System.out.println();
            aopExampleImpl2.enterAopExample();
            System.out.println();
            aopExampleImpl2.outAopExample();
        }
    }

一开始报错com.sun.proxy.$Proxy2 cannot be cast to com.terisadeng.spring.aop.AopExampleImpl1  
表示动态代理生成的类无法转换为自定义的实现类  
需要在aop:config标签中增加属性:proxy-target-class="true"