使用Sentinel对Spring MVC接口进行限流

<!--Sentinel 核心包-->
<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-core</artifactId>
    <version>${sentinel.version}</version>
</dependency>
<!--@SentinelResource注解AOP切面支持-->
<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-annotation-aspectj</artifactId>
    <version>${sentinel.version}</version>
</dependency>
<!--针对Spring MVC的适配器 Spring Webflux 可引入对应的适配器-->
<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-spring-webmvc-adapter</artifactId>
    <version>${sentinel.version}</version>
</dependency>
<!--负责同 dashboard 进行通信  如果你没有使用 sentinel dashboard 它是可选的-->
<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-transport-simple-http</artifactId>
    <version>${sentinel.version}</version>
</dependency>

// 规则对应的类为FlowRule，用List保存，可以有多个规则
List<FlowRule> rules = new ArrayList<>();
FlowRule flowRule = new FlowRule();
// 设置资源名称
flowRule.setResource("bar");
// QPS为2
flowRule.setCount(2);
// 需要在限流过滤器中设置对应的解析策略来获取
// flowRule.setLimitApp(appName);
//限流的类型
flowRule.setGrade(RuleConstant.FLOW_GRADE_QPS);
flowRule.setControlBehavior(CONTROL_BEHAVIOR_DEFAULT);
rules.add(flowRule);
FlowRuleManager.loadRules(rules);

// 1.5.0 版本开始可以利用 try-with-resources 特性（使用有限制）
// 资源名可使用任意有业务语义的字符串，比如方法名、接口名或其它可唯一标识的字符串。
try (Entry entry = SphU.entry("resourceName")) {
  // 被保护的业务逻辑
  // do something here...
} catch (BlockException ex) {
  // 资源访问阻止，被限流或被降级
  // 在此处进行相应的处理操作
}

@Bean
public SentinelResourceAspect sentinelResourceAspect() {
    return new SentinelResourceAspect();
}

@SentinelResource(value = "bar", entryType = EntryType.IN)
@GetMapping("/bar")
public String bar() {
    return "bar";
}

package cn.felord.sentinel.configuration;

import com.alibaba.csp.sentinel.adapter.spring.webmvc.SentinelWebInterceptor;
import com.alibaba.csp.sentinel.adapter.spring.webmvc.config.SentinelWebMvcConfig;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class GlobalSentinelWebMvcConfiguration implements WebMvcConfigurer {


    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        SentinelWebMvcConfig sentinelWebMvcConfig = new SentinelWebMvcConfig();
        //指定 请求方法 POST  GET 等等
        sentinelWebMvcConfig.setHttpMethodSpecify(true);
        //默认使用统一Web上下文   如果希望支持链路关系的流控策略则应该设置为false
        sentinelWebMvcConfig.setWebContextUnify(true);
        // 统一的 BlockException 处理  FlowException（BlockException） 会被 JVM 的 UndeclaredThrowableException 包裹一层  某种原因并不能捕获到异常
//        sentinelWebMvcConfig.setBlockExceptionHandler(new DefaultBlockExceptionHandler());
        // 用来标识来源 可针对性的对特定客户端的请求进行流控   limitApp
//        sentinelWebMvcConfig.setOriginParser(request -> request.getHeader("X-Client"));
 //       sentinelWebMvcConfig.setOriginParser(request -> request.getParameter("app"));

        //对原始的URL进行处理，比如去掉锚点之类的    /foo/bar?a=3#title  ->   /foo/bar?a=3
//        sentinelWebMvcConfig.setUrlCleaner( );
        registry.addInterceptor(new SentinelWebInterceptor(sentinelWebMvcConfig)).addPathPatterns("/**");
    }
}

/**
 * 捕获BlockException异常.
 */
@Slf4j
@ControllerAdvice
@Order(0)
public class SentinelControllerAdvice {
    /**
     * 异常处理.
     *
     * @param request the request
     * @param e       the e
     * @return the object
     */
    @ExceptionHandler(BlockException.class)
    @ResponseBody
    public ResponseEntity<?> sentinelBlockHandler(HttpServletRequest request, BlockException e) {
        log.warn("Blocked by Sentinel: {}", e.getRule());
        // Return the customized result.
        HashMap<String, Object> map = new HashMap<>();
        map.put("path", request.getServletPath());
        map.put("msg", "limited by sentinel");
        return ResponseEntity.status(HttpStatus.TOO_MANY_REQUESTS).body(map);
    }
}

java  -Dserver.port=8088     -jar .\sentinel-dashboard-1.8.0.jar

java -Dcsp.sentinel.dashboard.server=localhost:8088  -Dproject.name=sentinel-app -jar .\sentinel-spring-boot.jar