系統環境：

作業系統: win10

jdk版本:

openjdk version "12" 2019-03-19
OpenJDK Runtime Environment (build 12+33)
OpenJDK 64-Bit Server VM (build 12+33, mixed mode, sharing)

idea版本：

IntelliJ IDEA 2020.2.1 (Ultimate Edition)
Build #IU-202.6948.69, built on August 25, 2020
Licensed to hello
Subscription is active until September 11, 2021
For educational use only.
Runtime version: 11.0.8+10-b944.31 amd64
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.
Windows 10 10.0
GC: ParNew, ConcurrentMarkSweep
Memory: 966M
Cores: 8
Non-Bundled Plugins: Lombook Plugin, com.intellij.kubernetes, training

maven版本：3.6.3

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 https://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>2.3.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.rurjs.example</groupId>
    <artifactId>eureka</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>eureka</name>
    <description>Demo project for
 
 Spring Boot</description>

    <properties>
        <java.version>14</java.version>
        <spring-cloud.version>Hoxton.SR8</spring-cloud.version>
    </properties>

    <dependencies>
        <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>
            <optional>true
 
</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

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

</project>

切面類

package com.rurjs.example.eureka.aspect;

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

@Aspect
@Component
public class RjsAspectResponse {
    @Pointcut("@annotation(com.rurjs.example.eureka.aspect.RjsResponse)")
    private void makeResponse() {
//        return "hi";
    }

    /**
     * 定製一個環繞通知
     * @param joinPoint
     * @return
     */
    @Around("makeResponse()")
    public Object advice(ProceedingJoinPoint joinPoint) throws Throwable {
        System.out.println("Around Begin");
        Object res = (String) joinPoint.proceed();//執行到這裡開始走進來的方法體（必須宣告）

        System.out.println("Around End");
        return res;
    }

    //當想獲得註解裡面的屬性，可以直接注入該註解
    //方法可以帶引數，可以同時設定多個方法用&&
    @Before("makeResponse()")
    public void record(JoinPoint joinPoint) {
        System.out.println("Before");
    }

    @After("makeResponse()")
    public void after() {
        System.out.println("After");
    }

}

註解類

package com.rurjs.example.eureka.aspect;

import org.springframework.web.bind.annotation.Mapping;

import java.lang.annotation.*;

@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Mapping
public @interface RjsResponse {

    String value() default "";
}