Spring AOP - 注解方式实现

前文已经讨论了基于配置文件方式实现Spring AOP（Spring AOP - 配置文件方式实现），本文采用注解的方式实现前文相同的功能。配置步骤如下：

1、项目增加aop依赖（pom.xml)

        <dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>5.2.20.RELEASE</version></dependency><dependency><groupId>org.aspectj</groupId><artifactId>aspectjweaver</artifactId><version>1.9.6</version></dependency>

2、配置文件增加注解扫描的包（applicationContext.xml）

<?xml version="1.0" encoding="UTF-8"?>
<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="http://www.springframework.org/schema/beans"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context.xsdhttp://www.springframework.org/schema/aophttp://www.springframework.org/schema/aop/spring-aop.xsd"><!-- 扫描com.text包及子包下的注解--><context:component-scan base-package="com.text"/>
</beans>

3、增加切面类（开启切面注解@EnableAspectJAutoProxy、增加切面标识@Aspect）及通知方法（环绕通知@Around，并配置切点表达式execution）

package com.text.aspect;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
import org.springframework.stereotype.Component;
import java.util.Date;/*** 定义方法切面类*/
@EnableAspectJAutoProxy //开启AspectJ的注解方式
@Component
@Aspect //标识为切面类
public class MethodAspect {//配置环绕通知@Around("execution(public * com.text..*DaoImpl.*(..))")public void countMethodInvokeTime(ProceedingJoinPoint proceedingJoinPoint) {System.out.println("目标方法执行之前记录初始时间...");Date startTime = new Date();try {proceedingJoinPoint.proceed();//执行目标方法 即：StudentDaoImpl.getById方法System.out.println("目标方法执行之后记录结束时间...");String methodName = proceedingJoinPoint.getTarget().getClass().getName() + "." +proceedingJoinPoint.getSignature().getName();Date endTime = new Date();System.out.println(methodName + "方法执行总时长为：" + (endTime.getTime() - startTime.getTime()) + "毫秒");} catch (Throwable throwable) {throwable.printStackTrace();}}
}

4、业务方法StudentDaoImpl

package com.text.dao.impl;
import com.text.dao.StudentDao;
import org.springframework.stereotype.Repository;@Repository
public class StudentDaoImpl implements StudentDao {@Overridepublic void getById(String id) throws Exception {Thread.sleep(1000);System.out.println("查询学生id=" + id + "的信息");}
}

5、测试类Application

package com.text;import com.text.dao.StudentDao;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;public class Application {public static void main(String[] args) throws Exception {ApplicationContext context = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");StudentDao studentDao = context.getBean("studentDaoImpl", StudentDao.class);studentDao.getById("1");System.out.println("======getById end ========");}
}

6、程序运行结果