Spring Boot整合Guava 的 RateLimiter 实现接口限流

本项目展示了 Spring Boot 项目如何通过 AOP 结合 Guava 的 RateLimiter 实现接口限流，防止 API接口被恶意频繁请求。

一.创建新的springboot项目，引入pom文件。

<?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>2.2.7.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.dyz</groupId>
    <artifactId>retelimiter</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>retelimiter</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.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-starter-aop</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.3.3</version>
        </dependency>



        <!-- https://mvnrepository.com/artifact/com.google.guava/guava -->
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>28.2-jre</version>
        </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>

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

</project>

二、创建限流注解，@RateLimiter

/**
 * @author dyz
 * @version 1.0
 * @date 2020/5/11 15:40
 * 创建限流注解
 */
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RateLimiter {
    int NOT_LIMITED = 0;

    /**
     * qps
     */
    @AliasFor("qps") double value() default NOT_LIMITED;

    /**
     * qps
     */
    @AliasFor("value") double qps() default NOT_LIMITED;

    /**
     * 超时时长
     */
    int timeout() default 0;

    /**
     * 超时时间单位
     */
    TimeUnit timeUnit() default TimeUnit.MILLISECONDS;
}

三、配置限流切面

/**
 * @author dyz
 * @version 1.0
 * @date 2020/5/11 15:48
 *
 * 配置限流切面
 */
@Slf4j
@Aspect
@Component
public class RateLimiterAspect {
    private static final ConcurrentMap<String, com.google.common.util.concurrent.RateLimiter> RATE_LIMITER_CACHE = new ConcurrentHashMap<>();


    @Pointcut("@annotation(com.dyz.retelimiter.guava.annotation.RateLimiter)")
    public void rateLimit() {

    }

    @Around("rateLimit()")
    public Object pointcut(ProceedingJoinPoint point) throws Throwable {
        MethodSignature signature = (MethodSignature) point.getSignature();
        Method method = signature.getMethod();
        // 通过 AnnotationUtils.findAnnotation 获取 RateLimiter 注解
        RateLimiter rateLimiter = AnnotationUtils.findAnnotation(method, RateLimiter.class);
        if (rateLimiter != null && rateLimiter.qps() > RateLimiter.NOT_LIMITED) {
            double qps = rateLimiter.qps();
            if (RATE_LIMITER_CACHE.get(method.getName()) == null) {
                // 初始化 QPS
                RATE_LIMITER_CACHE.put(method.getName(), com.google.common.util.concurrent.RateLimiter.create(qps));
            }

            log.debug("【{}】的QPS设置为: {}", method.getName(), RATE_LIMITER_CACHE.get(method.getName()).getRate());
            // 尝试获取令牌
            if (RATE_LIMITER_CACHE.get(method.getName()) != null && !RATE_LIMITER_CACHE.get(method.getName()).tryAcquire(rateLimiter.timeout(), rateLimiter.timeUnit())) {
                throw new RuntimeException("请求频繁，请稍后再试~");
            }
        }
        return point.proceed();
    }

}

四、创建测试Controller

/**
 * @author dyz
 * @version 1.0
 * @date 2020/5/11 17:06
 */
@Slf4j
@RestController
public class TestController {


    /**
     * 开启限流
     * @return
     */
    @RateLimiter(value = 1.0, timeout = 100)
    @GetMapping("/rateLimiter")
    public String rateLimiter() {
        log.info("【rateLimiter】被执行了。。。。。");
        return "你不能总是看到我，快速刷新我看一下！";
    }


    /**
     * 未开启限流
     * @return
     */
    @GetMapping("/noRateLimiter")
    public String noRateLimiter() {
        log.info("【noRateLimiter】被执行了。。。。。");
        return "我没有被限流哦，一直刷新一直在.....";
    }

}