aop注解 自定义切面的注解写法

spring.xml中

<?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:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
                         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
                         http://www.springframework.org/schema/context
                         http://www.springframework.org/schema/context/spring-context-3.0.xsd
                         http://www.springframework.org/schema/tx
                         http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
                         http://www.springframework.org/schema/aop 
                         http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
<!--      扫描注解bean -->
     <context:component-scan base-package="cn.us.aspect"/>
<!--      开启切面代理 使得spring认识 @Aspect -->
     <aop:aspectj-autoproxy/>

 java文件中   无参数的

package cn.us.aspect;


import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;

import cn.us.domain.User;

@Component("logAspect")
@Aspect
public class LogAspect {
    // @Pointcut("execution(* cn.us.service.impl.UserServiceImpl.addUser(cn.us.domain.User)) and args(user)")   以下是无参数的写法
     @Pointcut("execution(* cn.us.service.impl.UserServiceImpl.*(..))")
     public void pointcut()
     {}
    // @Before("pointcut(user)")
      @Before("pointcut()")
    // public void startRecordLog(User user)
       public void startRecordLog()
     {
         System.out.println("Before log  has started");
         System.out.println();
     }

     @AfterReturning(value="pointcut()",returning="val")
     public void endRecordLog(Object val)
     {
         System.out.println("@AfterReturning log  has end");
         System.out.println(val);
     }
}

有参数的 利用 @Before和@After写法

有参数 传递的写法 @Before和 @After 的形参都要写上 参数

package cn.us.aspect;


import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.AfterReturning;
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;

import cn.us.domain.User;

@Component("logAspect")
@Aspect
public class LogAspect {
    // @Pointcut("execution(* cn.us.service.impl.UserServiceImpl.*(cn.us.domain.User)) and args(user)")
    @Pointcut(value="execution(* cn.us.service.impl.UserServiceImpl.addUser(cn.us.domain.User)) && args(user) ")
     public void pointcut(User user)
     {}
    //     @Before(value="pointcut(user)")
    //     public void startRecordLog(cn.us.domain.User user)
     // @Before("pointcut()")
     // public void startRecordLog()
     @Before(value="pointcut(user)")
     public void startRecordLog(User user)
     {
         System.out.println("Before log  has started");
         System.out.println(user);
     }

     @AfterReturning(value="pointcut(user)",returning="val")
     public void endRecordLog(User user,Object val)
     {
         User u=(User) val;                          //这里要强制类型转换，否则输出的位null ,没有强转调用object的，所以就为null了
         System.out.println("@AfterReturning log  has end");
         System.out.println(u);
     }
     
     @Around(value = "pointcut(user)")
     public void aroundRecordLog(ProceedingJoinPoint pjp,User user) throws Throwable
     {
         System.out.println("around before");
         //获取参数
         Object [] objs=pjp.getArgs();
         for(Object obj :objs)
         {
             System.out.println(obj);
         }
         //返回值
         Object oo=pjp.proceed();
        
         System.out.println("around after"  +oo);
     }
}

 无参数的写法，利用环绕通知

可以再环绕通知里 利用getArgs（）方法获取参数。并且输出

package cn.us.aspect;


import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.AfterReturning;
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;

import cn.us.domain.User;

@Component("logAspect")
@Aspect
public class LogAspect {
    // @Pointcut("execution(* cn.us.service.impl.UserServiceImpl.*(cn.us.domain.User)) and args(user)")
     @Pointcut(value="execution(* cn.us.service.impl.UserServiceImpl.addUser(..)) ")
     public void pointcut()
     {}

     @Around(value = "pointcut()")
     public void aroundRecordLog(ProceedingJoinPoint pjp) throws Throwable
     {
         System.out.println("around before");
         //获取参数
         Object [] objs=pjp.getArgs();
         for(Object obj :objs)
         {
             System.out.println(obj);
         }
         //返回值
         Object oo=pjp.proceed();
        
         System.out.println("around after"  +oo);
     }
}