基于注解实现spring AOP

springaop使用很简单，

一，配置文件

在spring的配置文件中激活组件扫描，激活自动代理功能

<?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:context="http://www.springframework.org/schema/context"
          xmlns:jms="http://www.springframework.org/schema/jms"
          xmlns:amq="http://activemq.apache.org/schema/core"
          xmlns:aop="http://www.springframework.org/schema/aop"
        xsi:schemaLocation=" http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd 
        	  http://activemq.apache.org/schema/core http://activemq.apache.org/schema/core/activemq-core-5.8.0.xsd
              http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd  
              http://www.springframework.org/schema/jms http://www.springframework.org/schema/jms/spring-jms-3.0.xsd
              http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd">  
        <!-- 激活组件扫描功能,在包cn.ysh.studio.spring.aop及其子包下面自动扫描通过注解配置的组件 -->
	<context:component-scan base-package="main.java.com.springaop"/>
	<!-- 激活自动代理功能 -->
	<aop:aspectj-autoproxy proxy-target-class="true"/>
	<!-- 用户服务对象 -->
	<bean name="service" class="main.java.com.springaop.DomainObject"/>
  </beans>

 二、需要代理的对象

这个对象必须是spring中注册的对象，也就是说必须是在spring配置文件中声明的对象

public class DomainObject {
	private String name = "d" ;
	public void show(){
		System.out.println("name="+name);
	}
}

 三、AOP实现

这是最核心的，代理对象的触发方法，方法运行前运行后的通知都在这里实现：

@Component
@Aspect
public class ServiceAspect {
	
	@Before("execution(* main.java.com.springaop.DomainObject.show(..))")
	public void beforDo(JoinPoint joinPoint){
		System.out.println("before");
	}
	
	@Around("execution(* main.java.com.springaop.DomainObject.show(..))")
	public void around(JoinPoint joinPoint){
		long start = System.currentTimeMillis();
		try {
			ProceedingJoinPoint jj = (ProceedingJoinPoint)joinPoint ;
			jj.proceed();
			long end = System.currentTimeMillis();
				System.out.println("around " + joinPoint + "\tUse time : " + (end - start) + " ms!");
		} catch (Throwable e) {
			long end = System.currentTimeMillis();
			System.out.println("around " + joinPoint + "\tUse time : " + (end - start) + " ms with exception : " + e.getMessage());
		}
	}
}

 这里只实现了两个方面，

测试代码

public class AopTest {
	public static void main(String[] args) {
		ApplicationContext ap = new ClassPathXmlApplicationContext("main/java/conf/applicationContext.xml");
		DomainObject obj = (DomainObject) ap.getBean("service");
		obj.show();
	}
}

 如此简单，为何不用