Spring Cloud Gateway 是基于 Netty，跟 Servlet 不兼容，所以你的工程中不能出现 Servlet 的组件 。

    1、pom.xml

    注意，一定不能出现 spring web 的依赖，因为 Gateway 与 Servlet 不兼容。

    1. <dependency>
    2.     <groupId>org.springframework.cloud</groupId>
    3.     <artifactId>spring-cloud-starter-gateway</artifactId>
    4. </dependency>

    2、application.yml

    1. server:
    2.   port: 8010
    3. spring:
    4.   application:
    5.     name: gateway
    6.   cloud:
    7.     gateway:
    8.       discovery:
    9.         locator:
    10.           enabled: true
    11.       routes: 
    12.         - id: provider_route   
    13.           uri: http://localhost:8081 
    14.           predicates: 
    15.             - Path=/provider/** 
    16.           filters:
    17.             - StripPrefix=1

    上面这种做法其实没有用到 nacos ，现在我们让 gateway 直接去 nacos 中发现服务，配置更加简单了。

    1、pom.xml 引入 nacos

    1. <dependency>
    2.     <groupId>org.springframework.cloud</groupId>
    3.     <artifactId>spring-cloud-starter-gateway</artifactId>
    4. </dependency>
    6. <dependency>
    7.     <groupId>com.alibaba.cloud</groupId>
    8.     <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    9. </dependency>

    2、application.yml

    1. server:
    2.   port: 8010
    3. spring:
    4.   application:
    5.     name: gateway
    6.   cloud:
    7.       gateway:
    8.         discovery:
    9.           locator:
    10.             enabled: true

    Gateway 限流

    基于路由限流

    1、pom.xml

    1. <dependency>
    2.     <groupId>org.springframework.cloud</groupId>
    3.     <artifactId>spring-cloud-starter-gateway</artifactId>
    4. </dependency>
    6. <dependency>
    7.     <groupId>com.alibaba.csp</groupId>
    8.     <artifactId>sentinel-spring-cloud-gateway-adapter</artifactId>
    9. </dependency>

    2、配置类

    1. package com.godfrey.configuration;
    3. import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayFlowRule;
    4. import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayRuleManager;
    5. import com.alibaba.csp.sentinel.adapter.gateway.sc.SentinelGatewayFilter;
    6. import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.BlockRequestHandler;
    7. import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.GatewayCallbackManager;
    8. import com.alibaba.csp.sentinel.adapter.gateway.sc.exception.SentinelGatewayBlockExceptionHandler;
    9. import org.springframework.beans.factory.ObjectProvider;
    10. import org.springframework.cloud.gateway.filter.GlobalFilter;
    11. import org.springframework.context.annotation.Bean;
    12. import org.springframework.context.annotation.Configuration;
    13. import org.springframework.core.Ordered;
    14. import org.springframework.core.annotation.Order;
    15. import org.springframework.http.HttpStatus;
    16. import org.springframework.http.MediaType;
    17. import org.springframework.http.codec.ServerCodecConfigurer;
    18. import org.springframework.web.reactive.function.BodyInserters;
    19. import org.springframework.web.reactive.function.server.ServerResponse;
    20. import org.springframework.web.reactive.result.view.ViewResolver;
    21. import org.springframework.web.server.ServerWebExchange;
    22. import reactor.core.publisher.Mono;
    24. import javax.annotation.PostConstruct;
    25. import java.util.*;
    27. /**
    28.  * @author godfrey
    29.  * @since 2020-12-27
    30.  */
    31. @Configuration
    32. public class GatewayConfiguration {
    33.     private final List<ViewResolver> viewResolvers;
    34.     private final ServerCodecConfigurer serverCodecConfigurer;
    37.     public GatewayConfiguration(ObjectProvider<List<ViewResolver>> viewResolversProvider,
    38.                                 ServerCodecConfigurer serverCodecConfigurer) {
    39.         this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);
    40.         this.serverCodecConfigurer = serverCodecConfigurer;
    41.     }
    43.     //配置限流的异常处理
    44.     @Bean
    45.     @Order(Ordered.HIGHEST_PRECEDENCE)
    46.     public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler() {
    47.         return new SentinelGatewayBlockExceptionHandler(viewResolvers, serverCodecConfigurer);
    48.     }
    50.     //配置初始化的限流参数
    51.     @PostConstruct
    52.     public void initGatewayRules(){
    53.         Set<GatewayFlowRule> rules = new HashSet<>();
    54.         rules.add(
    55.                 new GatewayFlowRule("provider_route")
    56.                         .setCount(1)
    57.                         .setIntervalSec(1)
    58.         );
    59.         GatewayRuleManager.loadRules(rules);
    60.     }
    62.     //初始化限流过滤器
    63.     @Bean
    64.     @Order(Ordered.HIGHEST_PRECEDENCE)
    65.     public GlobalFilter sentinelGatewayFilter() {
    66.         return new SentinelGatewayFilter();
    67.     }
    69.     //自定义限流异常页面
    70.     @PostConstruct
    71.     public void initBlockHandlers(){
    72.         BlockRequestHandler blockRequestHandler = new BlockRequestHandler() {
    73.             @Override
    74.             public Mono<ServerResponse> handleRequest(ServerWebExchange serverWebExchange, Throwable throwable) {
    75.                 Map map = new HashMap();
    76.                 map.put("code",0);
    77.                 map.put("msg","被限流了");
    78.                 return ServerResponse.status(HttpStatus.OK)
    79.                         .contentType(MediaType.APPLICATION_JSON)
    80.                         .body(BodyInserters.fromObject(map));
    81.             }
    82.         };
    83.         GatewayCallbackManager.setBlockHandler(blockRequestHandler);
    84.     }
    85. }

    3、application.yml

    1. server:
    2.   port: 8010
    3. spring:
    4.   application:
    5.     name: gateway
    6.   cloud:
    7.     gateway:
    8.       discovery:
    9.         locator:
    10.           enabled: true
    11.       routes:
    12.         - id: provider_route
    13.           uri: http://localhost:8081
    14.           predicates:
    15.             - Path=/provider/**
    16.           filters:
    17.             - StripPrefix=1

    基于 API 分组限流

    1、修改配置类，添加基于 API 分组限流的方法，修改初始化的限流参数

    1. package com.godfrey.configuration;
    3. import com.alibaba.csp.sentinel.adapter.gateway.common.SentinelGatewayConstants;
    4. import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiDefinition;
    5. import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiPathPredicateItem;
    6. import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiPredicateItem;
    7. import com.alibaba.csp.sentinel.adapter.gateway.common.api.GatewayApiDefinitionManager;
    8. import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayFlowRule;
    9. import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayRuleManager;
    10. import com.alibaba.csp.sentinel.adapter.gateway.sc.SentinelGatewayFilter;
    11. import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.BlockRequestHandler;
    12. import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.GatewayCallbackManager;
    13. import com.alibaba.csp.sentinel.adapter.gateway.sc.exception.SentinelGatewayBlockExceptionHandler;
    14. import org.springframework.beans.factory.ObjectProvider;
    15. import org.springframework.cloud.gateway.filter.GlobalFilter;
    16. import org.springframework.context.annotation.Bean;
    17. import org.springframework.context.annotation.Configuration;
    18. import org.springframework.core.Ordered;
    19. import org.springframework.core.annotation.Order;
    20. import org.springframework.http.HttpStatus;
    21. import org.springframework.http.MediaType;
    22. import org.springframework.http.codec.ServerCodecConfigurer;
    23. import org.springframework.web.reactive.function.BodyInserters;
    24. import org.springframework.web.reactive.function.server.ServerResponse;
    25. import org.springframework.web.reactive.result.view.ViewResolver;
    26. import org.springframework.web.server.ServerWebExchange;
    27. import reactor.core.publisher.Mono;
    29. import javax.annotation.PostConstruct;
    30. import java.util.*;
    32. /**
    33.  * @author godfrey
    34.  * @since 2020-12-27
    35.  */
    37. @Configuration
    38. public class GatewayConfiguration {
    40.     private final List<ViewResolver> viewResolvers;
    41.     private final ServerCodecConfigurer serverCodecConfigurer;
    44.     public GatewayConfiguration(ObjectProvider<List<ViewResolver>> viewResolversProvider,
    45.                                 ServerCodecConfigurer serverCodecConfigurer) {
    46.         this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);
    47.         this.serverCodecConfigurer = serverCodecConfigurer;
    48.     }
    50.     //配置限流的异常处理
    51.     @Bean
    52.     @Order(Ordered.HIGHEST_PRECEDENCE)
    53.     public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler() {
    54.         return new SentinelGatewayBlockExceptionHandler(viewResolvers, serverCodecConfigurer);
    55.     }
    57.     //配置初始化的限流参数
    58.     @PostConstruct
    59.     public void initGatewayRules(){
    60.         Set<GatewayFlowRule> rules = new HashSet<>();
    61.         rules.add(new GatewayFlowRule("provider_api1").setCount(1).setIntervalSec(1));
    62.         rules.add(new GatewayFlowRule("provider_api2").setCount(1).setIntervalSec(1));
    63.         GatewayRuleManager.loadRules(rules);
    64.     }
    66.     //初始化限流过滤器
    67.     @Bean
    68.     @Order(Ordered.HIGHEST_PRECEDENCE)
    69.     public GlobalFilter sentinelGatewayFilter() {
    70.         return new SentinelGatewayFilter();
    71.     }
    73.     //自定义限流异常页面
    74.     @PostConstruct
    75.     public void initBlockHandlers(){
    76.         BlockRequestHandler blockRequestHandler = new BlockRequestHandler() {
    77.             @Override
    78.             public Mono<ServerResponse> handleRequest(ServerWebExchange serverWebExchange, Throwable throwable) {
    79.                 Map map = new HashMap();
    80.                 map.put("code",0);
    81.                 map.put("msg","被限流了");
    82.                 return ServerResponse.status(HttpStatus.OK)
    83.                         .contentType(MediaType.APPLICATION_JSON)
    84.                         .body(BodyInserters.fromObject(map));
    85.             }
    86.         };
    87.         GatewayCallbackManager.setBlockHandler(blockRequestHandler);
    88.     }
    90.     //自定义API分组
    91.     @PostConstruct
    92.     private void initCustomizedApis(){
    93.         Set<ApiDefinition> definitions = new HashSet<>();
    94.         ApiDefinition api1 = new ApiDefinition("provider_api1")
    95.                 .setPredicateItems(new HashSet<ApiPredicateItem>(){{
    96.                     add(new ApiPathPredicateItem().setPattern("/provider/api1/**")
    97.                             .setMatchStrategy(SentinelGatewayConstants.URL_MATCH_STRATEGY_PREFIX));
    98.                 }});
    99.         ApiDefinition api2 = new ApiDefinition("provider_api2")
    100.                 .setPredicateItems(new HashSet<ApiPredicateItem>(){{
    101.                     add(new ApiPathPredicateItem().setPattern("/provider/api2/demo1"));
    102.                 }});
    103.         definitions.add(api1);
    104.         definitions.add(api2);
    105.         GatewayApiDefinitionManager.loadApiDefinitions(definitions);
    106.     }
    107. }

    2、Controller 添加方法

    1. @GetMapping("/api1/demo1")
    2. public String demo1() {
    3.     return "demo";
    4. }
    6. @GetMapping("/api1/demo2")
    7. public String demo2() {
    8.     return "demo";
    9. }
    11. @GetMapping("/api2/demo1")
    12. public String demo3() {
    13.     return "demo";
    14. }
    16. @GetMapping("/api2/demo2")
    17. public String demo4() {
    18.     return "demo";
    19. }

    也可以基于 Nacos 服务发现组件进行限流

    1. server:
    2.   port: 8010
    3. spring:
    4.   application:
    5.     name: gateway
    6.   cloud:
    7.     gateway:
    8.       discovery:
    9.         locator:
    10.           enabled: true

    API 分组代码修改，改为 discovery 中的服务名。

    1. ApiDefinition api2 = new ApiDefinition("provider_api2")
    2.         .setPredicateItems(new HashSet<ApiPredicateItem>(){{
    3.             add(new ApiPathPredicateItem().setPattern("/p1/api2/demo1"));
    4.         }});