四.Spring之AspectJ

一.使用AspectJ 实现AOP

注解方式实现AOP:

• AspectJ是一个基于Java语言的AOP框架;
• Spring2.0以后新增对AspectJ切点表达式支持;
• @AspectJ是AspectJ1.5新增功能,通过JDK1.5注解技术,允许直接在bean中定义切面;
• 新版本Spring框架,建议使用AspectJ方式来开发AOP;
• 使用AspectJ需要导入Spring AOP和AspectJ相关jar包

• 
      
        org.springframework
        spring-aop
        5.1.9.RELEASE
      
      
        aopalliance
        aopalliance
        1.0
      
  
  
      
        org.springframework
        spring-aspects
        4.1.7.RELEASE
      
      
        org.aspectj
        aspectjweaver
        1.8.13
      

  二.目录结构

三.注解开发:环境准备

• 四.增强类代码

package com.batac.demo1;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.*;

/**
 * 切面类
 */
@Aspect
public class MyAspectAnno {

//---------------------------------前置通知---------------------------------
    /**
     *
     */
//    1.ProductDao中所有的方法都会被增强
//    @Before(value = "execution(* com.batac.demo1.ProductDao.*(..))")
    //    2.ProductDao中的save方法会被前置增强;
    @Before(value = "execution(* com.batac.demo1.ProductDao.save(..))")
    public void  before(){
        System.out.println("前置通知");
    }

//    3.ProductDao中的save方法会被前置增强;参数:获取连接点
    @Before(value = "execution(* com.batac.demo1.ProductDao.save(..))")
    public void  before(JoinPoint joinPoint){
        System.out.println("前置通知" + joinPoint);
    }

//---------------------------------后置通知---------------------------------
    @AfterReturning(value = "execution(* com.batac.demo1.ProductDao.delete(..))")
    public void afterReturint(){
        System.out.println("---后置通知---");
    }
//    获取返回数据
    @AfterReturning(value = "execution(* com.batac.demo1.ProductDao.delete(..))",returning = "result")
    public void afterReturint(Object result){
        System.out.println("---后置通知---" + result);
    }


    //---------------------------------环绕通知---------------------------------
//环绕通知
    @Around(value = "execution(* com.batac.demo1.ProductDao.find(..))")
    public Object around(ProceedingJoinPoint joinPoint) throws Throwable {
        System.out.println("环绕前");
        Object object =  (Object) joinPoint.proceed();//执行目标方法
        System.out.println("环绕后");
        return object;
    }

//    异常通知
    @AfterThrowing(value = "execution(* com.batac.demo1.ProductDao.find(..))",throwing = "e")
    public void afterThrowing(Throwable e){
        System.out.println("异常抛出通知:" + e.getMessage());
    }

}

五.需要增强的类:

package com.batac.demo1;

public class ProductDao {

    public void save(){
        System.out.println("save");
    }

    public String delete(){
        System.out.println("delete");
        return "Nihao";
    }

    public void update(){
        System.out.println("update");
    }

    public void find(){
        System.out.println("find");
//        int a = 10/0;
    }
}

六.测试类

package com.batac.demo1;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import javax.annotation.Resource;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class ProductDaoTest {

    @Resource(name = "productDao")
    private ProductDao productDao;

    @Test
    public void demo1(){
        productDao.delete();
        productDao.find();
        productDao.save();
        productDao.update();

    }
}

七.打印结果