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Spring Cloud Gateway实战：微服务API网关从零到一

news 2026/5/27 14:45:53

前言

Spring Cloud Gateway 是 Spring 官方推出的 API 网关，基于 WebFlux 实现，性能卓越。本文带你从零搭建一个生产级的微服务 API 网关。

一、核心概念

Route（路由）：网关的基本构建块，包含 ID、目标 URI、Predicate、Filter
Predicate（断言）：匹配请求条件（路径、Header、参数等）
Filter（过滤器）：对请求进行前置/后置处理（鉴权、限流、日志等）

二、快速搭建

<!-- pom.xml -->
<dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-gateway</artifactId>
</dependency># application.yml
server:port: 8080spring:application:name: api-gatewaycloud:gateway:routes:- id: user-serviceuri: lb://user-servicepredicates:- Path=/api/users/**filters:- StripPrefix=1- id: order-serviceuri: lb://order-servicepredicates:- Path=/api/orders/**filters:- StripPrefix=1discovery:locator:enabled: true  # 自动发现服务

三、自定义全局过滤器（JWT 鉴权）

@Component
public class AuthGlobalFilter implements GlobalFilter, Ordered {@Overridepublic Mono<Void> filter(ServerWebExchange exchange,GatewayFilterChain chain) {String path = exchange.getRequest().getPath().value();// 白名单路径跳过鉴权if (path.startsWith("/api/auth/login") ||path.startsWith("/api/auth/register")) {return chain.filter(exchange);}String token = exchange.getRequest().getHeaders().getFirst("Authorization");if (token == null || !token.startsWith("Bearer ")) {exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);return exchange.getResponse().setComplete();}// 验证 JWT（简化示例）try {String jwt = token.substring(7);Claims claims = Jwts.parser().setSigningKey("secret-key").parseClaimsJws(jwt).getBody();String userId = claims.getSubject();ServerHttpRequest request = exchange.getRequest().mutate().header("X-User-Id", userId).build();return chain.filter(exchange.mutate().request(request).build());} catch (Exception e) {exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);return exchange.getResponse().setComplete();}}@Overridepublic int getOrder() { return -100; }
}

四、自定义 GatewayFilter（限流）

@Component
public class RateLimitFilter implements GatewayFilter, Ordered {private final RateLimiter rateLimiter = RateLimiter.create(100);@Overridepublic Mono<Void> filter(ServerWebExchange exchange,GatewayFilterChain chain) {if (!rateLimiter.tryAcquire()) {exchange.getResponse().setStatusCode(HttpStatus.TOO_MANY_REQUESTS);return exchange.getResponse().setComplete();}return chain.filter(exchange);}@Overridepublic int getOrder() { return 0; }
}# 在路由中使用自定义过滤器
spring.cloud.gateway.routes[0].filters:- name: RateLimitargs:redis-rate-limiter.replenishRate: 10redis-rate-limiter.burstCapacity: 20

五、跨域配置

@Configuration
public class CorsConfig {@Beanpublic CorsWebFilter corsWebFilter() {CorsConfiguration config = new CorsConfiguration();config.addAllowedOrigin("*");config.addAllowedHeader("*");config.addAllowedMethod("*");config.setAllowCredentials(true);UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();source.registerCorsConfiguration("/**", config);return new CorsWebFilter(source);}
}

六、网关 vs Nginx

# Nginx：反向代理 + 负载均衡
# 适合：静态资源、SSL 终止、四层/七层负载均衡# Spring Cloud Gateway：业务网关
# 适合：动态路由、JWT 鉴权、限流、熔断、灰度发布# 生产推荐：Nginx（前置）+ Gateway（后置）
# 请求链路：Client → Nginx → Gateway → Microservice