springboot-aop-示例实现，并讨论多个切面的多个切点的执行顺序

1 创建项目

STS工具
file,new,spring starter project

2 pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.1.4.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.zfh</groupId>
	<artifactId>springAOP-8</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>springAOP-8</name>
	<description>Demo project for Spring Boot</description>

	<properties>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<!-- 添加web支持 -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		
		<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-aop -->
		<!-- 添加aop支持 -->
		<dependency>
		    <groupId>org.springframework.boot</groupId>
		    <artifactId>spring-boot-starter-aop</artifactId>
		</dependency>
		
		
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

3 核心业务

package com.fhzheng.demo.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class DoHomeWorkController {
	@GetMapping("/dohomework")
	public void doHomeWork(String name) {
		System.out.println(name + "Method:做家庭作业，这是核心任务... ...");
	}
}

4 切面1

package com.fhzheng.demo.aspect;

import javax.servlet.http.HttpServletRequest;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
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.core.annotation.Order;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

@Order(1)
@Aspect
@Component
public class DoHomeWorkAspect {
	/** 定义切入点 */
	@Pointcut("execution(* com.fhzheng.demo.controller.DoHomeWorkController.doHomeWork(..))")
	public void homeWorkPointcut() {
	}
 
	/** 定义Before advice通知类型处理方法  */
	@Before("homeWorkPointcut()")
	public void beforeHomeWork() {
		ServletRequestAttributes requestAttributes = 
				(ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
		HttpServletRequest request = requestAttributes.getRequest();
		System.out.println("Aspect1:Before "+request.getParameter("name") + "回家思考先要做什么事，想先吃个冰淇淋......");
	}
	
	/** 定义Around advice通知类型处理方法   */
	@Around("homeWorkPointcut()")
	public void around(ProceedingJoinPoint joinPoint) {
		System.out.println("Aspect1:Around 回家思考的环绕通知，方法执行前");
		try {
			joinPoint.proceed();
		} catch (Throwable e) {
			e.printStackTrace();
		}
		System.out.println("Aspect1:Around 回家思考的环绕通知，方法执行后");
	}
	
	/** 定义AfterReturning advice通知类型处理方法  */
	@AfterReturning("homeWorkPointcut()")
	public void afterReturningHomeWork() {
		System.out.println("Aspect1:AfterReturning 回家思考的正常返回后通知，方法执行后");
	}
	
	/** 定义After advice通知类型处理方法  */
	@After("homeWorkPointcut()")
	public void afterHomeWork() {
		System.out.println("Aspect1:After 回家思考的最终返回后通知，方法执行后");
	}
	

}

5 切面2

package com.fhzheng.demo.aspect;

import javax.servlet.http.HttpServletRequest;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
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.core.annotation.Order;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

@Order(2)
@Aspect
@Component
public class DoHomeWorkPrepare {
	/** 定义切入点 */
	@Pointcut("execution(* com.fhzheng.demo.controller.*.*(..))")
	public void prepare() {
	}
 
	/** 定义Before advice通知类型处理方法  */
	@Before("prepare()")
	public void beforeHomeWork() {
		ServletRequestAttributes requestAttributes = 
				(ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
		HttpServletRequest request = requestAttributes.getRequest();
		System.out.println("Aspect2:Before "+request.getParameter("name") + "换上做清洁工作的套装......");
	}
	
	/** 定义Around advice通知类型处理方法   */
	@Around("prepare()")
	public void around(ProceedingJoinPoint joinPoint) {
		System.out.println("Aspect2:Around 做清洁工作的环绕通知，方法执行前");
		try {
			joinPoint.proceed();
		} catch (Throwable e) {
			e.printStackTrace();
		}
		System.out.println("Aspect2:Around 做清洁工作的环绕通知，方法执行后");
	}
	
	/** 定义AfterReturning advice通知类型处理方法  */
	@AfterReturning("prepare()")
	public void afterReturningHomeWork() {
		System.out.println("Aspect2:AfterReturning 清洁工作的正常返回后通知，方法执行后");
	}
	
	/** 定义After advice通知类型处理方法  */
	@After("prepare()")
	public void afterHomeWork() {
		System.out.println("Aspect2:After 清洁工作的最终返回后通知，方法执行后");
	}

}

6 运行

7 结果

8 一个个切面的执行顺序

Around–>Before–>Around–>After–>AfterReturning
–>AfterThrowing

9 多个切面的执行顺序

有点类似于过滤器的执行顺序

可以看到Aspect1 和Aspect2两个切面类中所有通知类型的执行顺序，Method是具体的切入点，order代表优先级，它根据一个int值来判断优先级的高低，数字越小，优先级越高！所以，不同的切面，实际上是环绕于切入点的同心圆：

在真实的业务应用中，切面有多个时，需要以实际跑出来的顺序为准啊。