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);
      }
 }