✨ spring-boot-demo-ratelimit-guava 完成

spring-boot-demo-ratelimit-guava/README.md

@@ -1,2 +1,215 @@
 # spring-boot-demo-ratelimit-guava
 
+> 此 demo 主要演示了 Spring Boot 项目如何通过 AOP 结合 Guava 的 RateLimiter 实现限流，旨在保护 API 被恶意频繁访问的问题。
+
+## 1. 主要代码
+
+### 1.1. pom.xml
+
+```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>
+
+  <artifactId>spring-boot-demo-ratelimit-guava</artifactId>
+  <version>1.0.0-SNAPSHOT</version>
+  <packaging>jar</packaging>
+
+  <name>spring-boot-demo-ratelimit-guava</name>
+  <description>Demo project for Spring Boot</description>
+
+  <parent>
+    <groupId>com.xkcoding</groupId>
+    <artifactId>spring-boot-demo</artifactId>
+    <version>1.0.0-SNAPSHOT</version>
+  </parent>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+    <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>cn.hutool</groupId>
+      <artifactId>hutool-all</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>com.google.guava</groupId>
+      <artifactId>guava</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-test</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+      <optional>true</optional>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <finalName>spring-boot-demo-ratelimit-guava</finalName>
+    <plugins>
+      <plugin>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-maven-plugin</artifactId>
+      </plugin>
+    </plugins>
+  </build>
+
+</project>
+```
+
+### 1.2. 定义一个限流注解 `RateLimiter.java`
+
+> 注意代码里使用了 `AliasFor` 设置一组属性的别名，所以获取注解的时候，需要通过 `Spring` 提供的注解工具类 `AnnotationUtils` 获取，不可以通过 `AOP` 参数注入的方式获取，否则有些属性的值将会设置不进去。
+
+```java
+/**
+ * <p>
+ * 限流注解，添加了 {@link AliasFor} 必须通过 {@link AnnotationUtils} 获取，才会生效
+ *
+ * @author yangkai.shen
+ * @date Created in 2019/9/12 14:14
+ * @see AnnotationUtils
+ * </p>
+ */
+@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;
+}
+```
+
+### 1.3. 定义一个切面 `RateLimiterAspect.java`
+
+```java
+/**
+ * <p>
+ * 限流切面
+ * </p>
+ *
+ * @author yangkai.shen
+ * @date Created in 2019/9/12 14:27
+ */
+@Slf4j
+@Aspect
+@Component
+public class RateLimiterAspect {
+    private static final com.google.common.util.concurrent.RateLimiter RATE_LIMITER = com.google.common.util.concurrent.RateLimiter.create(Double.MAX_VALUE);
+
+    @Pointcut("@annotation(com.xkcoding.ratelimit.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();
+            log.debug("【{}】的QPS设置为: {}", method.getName(), qps);
+            // 重新设置 QPS
+            RATE_LIMITER.setRate(qps);
+            // 尝试获取令牌
+            if (!RATE_LIMITER.tryAcquire(rateLimiter.timeout(), rateLimiter.timeUnit())) {
+                throw new RuntimeException("手速太快了，慢点儿吧~");
+            }
+        }
+        return point.proceed();
+    }
+}
+```
+
+### 1.4. 定义两个API接口用于测试限流
+
+```java
+/**
+ * <p>
+ * 测试
+ * </p>
+ *
+ * @author yangkai.shen
+ * @date Created in 2019/9/12 14:22
+ */
+@Slf4j
+@RestController
+public class TestController {
+
+    @RateLimiter(value = 1.0, timeout = 300)
+    @GetMapping("/test1")
+    public Dict test1() {
+        log.info("【test1】被执行了。。。。。");
+        return Dict.create().set("msg", "hello,world!").set("description", "别想一直看到我，不信你快速刷新看看~");
+    }
+
+    @GetMapping("/test2")
+    public Dict test2() {
+        log.info("【test2】被执行了。。。。。");
+        return Dict.create().set("msg", "hello,world!").set("description", "我一直都在，卟离卟弃");
+    }
+}
+```
+
+## 2. 测试
+
+- test1 接口未被限流的时候
+
+<img src="assets/image-20190912155209716.png" alt="image-20190912155209716" style="zoom:50%;" />
+
+- test1 接口频繁刷新，触发限流的时候
+
+<img src="assets/image-20190912155229745.png" alt="image-20190912155229745" style="zoom:50%;" />
+
+- test2 接口不做限流，可以一直刷新
+
+<img src="assets/image-20190912155146012.png" alt="image-20190912155146012" style="zoom:50%;" />
+
+## 3. 参考
+
+- [限流原理解读之guava中的RateLimiter](https://juejin.im/post/5bb48d7b5188255c865e31bc)
+
+- [使用Guava的RateLimiter做限流](https://my.oschina.net/hanchao/blog/1833612)
+