Spring AOP基於注解的“零配置”方式實現

1. 為了在Spring中啟動@AspectJ支持，需要在類加載路徑下新增兩個AspectJ庫：aspectjweaver.jar和aspectjrt.jar。除此之外，Spring AOP還需要依賴一個aopalliance.jar包
2. 定義一個類似ServiceAspect.java這樣的切面bean:

3. package com.hyq.aop;
   
   import org.apache.commons.logging.Log;
   import org.apache.commons.logging.LogFactory;
   import org.aspectj.lang.JoinPoint;
   import org.aspectj.lang.ProceedingJoinPoint;
   import org.aspectj.lang.annotation.After;
   import org.aspectj.lang.annotation.AfterReturning;
   import org.aspectj.lang.annotation.AfterThrowing;
   import org.aspectj.lang.annotation.Around;
   import org.aspectj.lang.annotation.Aspect;
   import org.aspectj.lang.annotation.Before;
   import org.aspectj.lang.annotation.Pointcut;
   import org.springframework.stereotype.Component;
   
   /**
    * 系統服務組件Aspect切面Bean
    * @author Shenghany
    */
   //聲明這是一個組件
   @Component
   //聲明這是一個切面Bean
   @Aspect
   public class ServiceAspect {
   
       private final static Log log = LogFactory.getLog(ServiceAspect.class);
   
       //配置切入點,該方法無方法體,主要為方便同類中其他方法使用此處配置的切入點
       @Pointcut("execution(* com.hyq.aop..*(..))")
       public void aspect(){    }
   
       /*
        * 配置前置通知,使用在方法aspect()上注冊的切入點
        * 同時接受JoinPoint切入點對象,可以沒有該參數
        */
       @Before("aspect()")
       public void before(JoinPoint joinPoint){
           System.out.println("執行before.....");
       }
   
       //配置后置通知,使用在方法aspect()上注冊的切入點
       @After("aspect()")
       public void after(JoinPoint joinPoint){
           System.out.println("執行after.....");
       }
   
       //配置環繞通知,使用在方法aspect()上注冊的切入點
       @Around("aspect()")
       public void around(JoinPoint joinPoint){
           long start = System.currentTimeMillis();
           try {
               ((ProceedingJoinPoint) joinPoint).proceed();
               long end = System.currentTimeMillis();
               if(log.isInfoEnabled()){
                   log.info("around " + joinPoint + "\tUse time : " + (end - start) + " ms!");
               }
           } catch (Throwable e) {
               long end = System.currentTimeMillis();
               if(log.isInfoEnabled()){
                   log.info("around " + joinPoint + "\tUse time : " + (end - start) + " ms with exception : " + e.getMessage());
               }
           }
       }
   
       //配置后置返回通知,使用在方法aspect()上注冊的切入點
       @AfterReturning("aspect()")
       public void afterReturn(JoinPoint joinPoint){
           if(log.isInfoEnabled()){
               log.info("afterReturn " + joinPoint);
           }
       }
   
       //配置拋出異常后通知,使用在方法aspect()上注冊的切入點
       @AfterThrowing(pointcut="aspect()", throwing="ex")
       public void afterThrow(JoinPoint joinPoint, Exception ex){
           if(log.isInfoEnabled()){
               log.info("afterThrow " + joinPoint + "\t" + ex.getMessage());
           }
       }
   
   }

   3.定義一個業務組件，如：

4. package com.hyq.aop;
   
   import org.apache.commons.logging.Log;
   import org.apache.commons.logging.LogFactory;
   import org.springframework.stereotype.Component;
   @Component()
   public class UserService {
   
       private final static Log log = LogFactory.getLog(UserService.class);
       
       public User get(long id){
           if(log.isInfoEnabled()){
               log.info("getUser method . . .");
           }
           return new User();
       }
       
       public void save(User user){
           if(log.isInfoEnabled()){
               log.info("saveUser method . . .");
           }
       }
       
       public boolean delete(long id) throws Exception{
           if(log.isInfoEnabled()){
               log.info("delete method . . .");
               throw new Exception("spring aop ThrowAdvice演示");
           }
           return false;
       }
       
   }

   業務組件要用@Component()注解修飾

　　　　4.在bean.xml中加入下面配置:

<!-- 激活組件掃描功能,在包com.hyq.aop及其子包下面自動掃描通過注解配置的組件 -->
    <context:component-scan base-package="com.hyq.aop"/>
    <!-- 激活自動代理功能 -->
    <!-- <aop:aspectj-autoproxy proxy-target-class="true"/> -->
    <aop:aspectj-autoproxy/>