spring 基于注解实现Aop

一.基于spirng的注解实现Aop的开发步骤

1.1 在pom文件中添加依赖

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <!-- spring framework -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>5.0.2.RELEASE</version>
    </dependency>

    <dependency>
      <groupId>org.aspectj</groupId>
      <artifactId>aspectjweaver</artifactId>
      <version>1.8.7</version>
    </dependency>
  </dependencies>

1.2 创建目标类

1. iAccountService接口

package com.ljf.spring.aop.anno.service;

public interface IAccountService {
    /**
     * 模拟保存账户
     */
    void saveAccount();

    /**
     * 模拟更新账户
     * @param i
     */
    void updateAccount(int i);

    /**
     * 删除账户
     * @return
     */
    int  deleteAccount();
}

2. 实现类

package com.ljf.spring.aop.anno.service.impl;

import com.ljf.spring.aop.anno.service.IAccountService;
import org.springframework.stereotype.Service;

/**
 * @ClassName: AccountService
 * @Description: TODO
 * @Author: liujianfu
 * @Date: 2021/02/05 10:41:48 
 * @Version: V1.0
 **/
@Service("accountService")
public class AccountService implements IAccountService {
    @Override
    public void saveAccount() {
        System.out.println("执行了保存");
        int i=1/0;
    }

    @Override
    public void updateAccount(int i) {
        System.out.println("执行了更新"+i);

    }

    @Override
    public int deleteAccount() {
        System.out.println("执行了删除");
        return 0;
    }
}

1.3 创建切面类

在切面类中定义切入点、通知、切面

package com.ljf.spring.aop.anno.util;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.*;
import org.springframework.stereotype.Component;

/**
 * @ClassName: Logger
 * @Description: TODO
 * @Author: liujianfu
 * @Date: 2021/02/05 10:45:13 
 * @Version: V1.0
 **/
@Component("logger")
@Aspect//表示当前类是一个切面类
public class Logger {
    //切入点
    @Pointcut("execution(* com.ljf.spring.aop.anno.service.impl.*.*(..))")
    private void pt1(){}   //作用是切点表达式的抽取

    /**
     * 前置通知
     */
  // @Before("pt1()")
    public  void beforePrintLog(){
        System.out.println("前置通知Logger类中的beforePrintLog方法开始记录日志了。。。");
    }

    /**
     * 后置通知
     */
//    @AfterReturning("pt1()")
    public  void afterReturningPrintLog(){
        System.out.println("后置通知Logger类中的afterReturningPrintLog方法开始记录日志了。。。");
    }
    /**
     * 异常通知
     */
    //@AfterThrowing("pt1()")
    public  void afterThrowingPrintLog(){
        System.out.println("异常通知Logger类中的afterThrowingPrintLog方法开始记录日志了。。。");
    }

    /**
     * 最终通知
     */
//    @After("pt1()")
    public  void afterPrintLog(){
        System.out.println("最终通知Logger类中的afterPrintLog方法开始记录日志了。。。");
    }


    @Around("pt1()")
    public Object aroundPringLog(ProceedingJoinPoint pjp){
        Object rtValue = null;
        try{
            Object[] args = pjp.getArgs();//得到方法执行所需的参数

            System.out.println("Logger类中的aroundPringLog方法开始记录日志了。。。前置");

            rtValue = pjp.proceed(args);//明确调用业务层方法（切入点方法）

            System.out.println("Logger类中的aroundPringLog方法开始记录日志了。。。后置");

            return rtValue;
        }catch (Throwable t){
            System.out.println("Logger类中的aroundPringLog方法开始记录日志了。。。异常");
            throw new RuntimeException(t);
        }finally {
            System.out.println("Logger类中的aroundPringLog方法开始记录日志了。。。最终");
        }
    }
}

1.4 在xml配置文件中开启Aop注解

<?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:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">

    <!-- 配置spring创建容器时要扫描的包-->
    <context:component-scan base-package="com.ljf"></context:component-scan>

    <!-- 配置spring开启注解AOP的支持 -->
    <aop:aspectj-autoproxy></aop:aspectj-autoproxy>
</beans>

1.5 调用

package com.ljf.spring.aop.anno;

import com.ljf.spring.aop.anno.service.IAccountService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Hello world!
 *
 */
public class App 
{
    public static void main(String[] args) {
        //1.获取容器
        ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");
        //2.获取对象
        IAccountService as = (IAccountService)ac.getBean("accountService");
        //3.执行方法
        as.saveAccount();
    }
}

使用了环绕通知：