Spring Cloud Gateway集成Sentinel流控详情

        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>

        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-spring-cloud-gateway-adapter</artifactId>
            <version>1.8.3</version>
        </dependency>

package cuit.epoch.pymjl.config;

import java.util.Collections;
import java.util.HashMap;
import java.util.List;

import javax.annotation.PostConstruct;

import com.alibaba.csp.sentinel.adapter.gateway.sc.SentinelGatewayFilter;
import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.BlockRequestHandler;
import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.GatewayCallbackManager;
import com.alibaba.csp.sentinel.adapter.gateway.sc.exception.SentinelGatewayBlockExceptionHandler;

import org.springframework.beans.factory.ObjectProvider;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.codec.ServerCodecConfigurer;
import org.springframework.web.reactive.function.BodyInserters;
import org.springframework.web.reactive.function.server.ServerResponse;
import org.springframework.web.reactive.result.view.ViewResolver;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;
/**
 * @author Pymjl
 * @version 1.0
 * @date 2022/9/15 14:15
 **/
@Configuration
public class GatewayConfiguration {
    private final List<ViewResolver> viewResolvers;
    private final ServerCodecConfigurer serverCodecConfigurer;
​
    /**
     * 这里ServerCodecConfigurer会报错：“Could not autowire. No beans of 'ServerCodecConfigurer' type found.”
     * 不影响使用，可以忽略他
     * sentinel拦截包括了视图、静态资源等，需要配置viewResolvers以及拦截之后的异常，我们也可以自定义抛出异常的提示
     *
     * @param viewResolversProvider 视图解析器供应器
     * @param serverCodecConfigurer 服务器编解码器配置
     */
    public GatewayConfiguration(ObjectProvider<List<ViewResolver>> viewResolversProvider,
                                ServerCodecConfigurer serverCodecConfigurer) {
        this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);
        this.serverCodecConfigurer = serverCodecConfigurer;
    }
​
    /**
     * 由于sentinel的工作原理其实借助于全局的filter进行请求拦截并计算出是否进行限流、熔断等操作的，增加SentinelGateWayFilter配置
     *
     * @return {@code SentinelGatewayBlockExceptionHandler}
     */
    @Bean
    @Order(Ordered.HIGHEST_PRECEDENCE)
    public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler() {
        // Register the block exception handler for Spring Cloud Gateway.
        return new SentinelGatewayBlockExceptionHandler(viewResolvers, serverCodecConfigurer);
    }
    @Bean
    @Order(-1)
    public GlobalFilter sentinelGatewayFilter() {
        return new SentinelGatewayFilter();
    }
​
    @PostConstruct
    public void doInit() {
        initCustomizedApis();
    }
​
    /**
     * 自定义异常提示：当发生限流异常时，会返回定义的提示信息。
     */
    private void initCustomizedApis() {
        BlockRequestHandler blockRequestHandler = new BlockRequestHandler() {
            @Override
            public Mono<ServerResponse> handleRequest(ServerWebExchange serverWebExchange, Throwable throwable) {
                // 自定义异常处理
                HashMap<String, String> map = new HashMap<>();
                map.put("code", "10099");
                map.put("message", "服务器忙，请稍后再试！");
                return ServerResponse.status(HttpStatus.NOT_ACCEPTABLE)
                        .contentType(MediaType.APPLICATION_JSON)
                        .body(BodyInserters.fromValue(map));
            }
        };
        GatewayCallbackManager.setBlockHandler(blockRequestHandler);
    }
}

    @PostConstruct
    public void doInit() {
        initCustomizedApis();
    }
    private void initCustomizedApis() {
        Set<ApiDefinition> definitions = new HashSet<>();
        ApiDefinition api1 = new ApiDefinition("some_customized_api")
            .setPredicateItems(new HashSet<ApiPredicateItem>() {{
                add(new ApiPathPredicateItem().setPattern("/ahas"));
                add(new ApiPathPredicateItem().setPattern("/product/**")
                    .setMatchStrategy(SentinelGatewayConstants.URL_MATCH_STRATEGY_PREFIX));
            }});
        ApiDefinition api2 = new ApiDefinition("another_customized_api")
            .setPredicateItems(new HashSet<ApiPredicateItem>() {{
                add(new ApiPathPredicateItem().setPattern("/**")
                    .setMatchStrategy(SentinelGatewayConstants.URL_MATCH_STRATEGY_PREFIX));
            }});
        definitions.add(api1);
        definitions.add(api2);
        GatewayApiDefinitionManager.loadApiDefinitions(definitions);
    }

spring:
  application:
    name: gateway-service
  cloud:
    loadbalancer:
      nacos:
        enabled: true
    nacos:
      discovery:
        server-addr: 192.168.199.128:8848 #Nacos地址
      config:
        server-addr: 192.168.199.128:8848 #Nacos地址
        file-extension: yaml #这里我们获取的yaml格式的配置
    gateway:
      discovery:
        locator:
          enabled: true
    sentinel:
      filter:
        enabled: false
      transport:
        #配置 Sentinel dashboard 地址
        dashboard: 192.168.199.128:8858
        #默认8719端口，假如被占用会自动从8719开始依次 1扫描,直至找到未被占用的端口
        port: 8719

spring:
  cloud:
    gateway:
    # 全局的过滤器，跨域配置
      default-filters:
        - DedupeResponseHeader=Access-Control-Allow-Origin, RETAIN_UNIQUE
      globalcors:
        cors-configurations:
          '[/**]':
            allowedHeaders: '*'
            allowedMethods: '*'
            allowedOrigins: '*'
      # 路由
      routes:
        - id: user_servcie_get
          uri: lb://user-service
          predicates:
            - Path=/user/get/{id}
        - id: user_service_test
          uri: lb://user-service
          predicates:
            - Path=/user/test