spring的APO注解方式

一、配置

　　1、xml配置方式

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        https://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd">

    <context:component-scan base-package="com.wuxi"></context:component-scan>

    <aop:aspectj-autoproxy></aop:aspectj-autoproxy>

</beans>

　　2、配置类方式

package com.wuxi.configs;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;

@Configuration
@ComponentScan("com.wuxi")
@EnableAspectJAutoProxy
public class SpringConfig {
}

二、增强的功能所在的类（通知类）

package com.wuxi.utils;

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

/*
@Before、@AfterReturning、@AfterThrowing、@After会有顺序问题（最终通知会在异常或后置通知之前执行），
使用@Around可以避免顺序问题
*/
@Component
@Aspect
public class LoggerService {

    @Pointcut("execution(public void com.wuxi.services.impl.StudentServiceImpl.removeStudent())")
    private void pt() {
    }

    @Before("pt()")
    public void printLog() {
        System.out.println("打印日志");
    }

    @Around("execution(public String com.wuxi.services.impl.StudentServiceImpl.findStudent())")
    public Object printAroundLog(ProceedingJoinPoint pjp) {
        Object proceed = null;
        try {
            System.out.println("环绕前置通知");
            Object[] args = pjp.getArgs();
            proceed = pjp.proceed(args);
            System.out.println("环绕后置通知");
        } catch (Throwable throwable) {
            System.out.println("环绕异常通知");
            throwable.printStackTrace();
        } finally {
            System.out.println("环绕最终通知");
        }
        return proceed;
    }
}

三、测试

package com.wuxi.tests;

import com.wuxi.configs.SpringConfig;
import com.wuxi.services.StudentService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MySpringTest {
    public static void main(String[] args) {
        // ApplicationContext ac = new ClassPathXmlApplicationContext("application.xml");
        ApplicationContext ac = new AnnotationConfigApplicationContext(SpringConfig.class);

        StudentService studentService = (StudentService) ac.getBean("studentServiceImpl");
        // studentService.removeStudent();
        studentService.findStudent();
    }
}