Spring Cloud 学习 - Gateway新一代网关

旧城等待， 2023-07-18 02:55 12阅读 0赞

# Spring Cloud Gateway 新一代网关 #

> Spring Cloud Gateway 是Spring Cloud的一个全新项目，基于Spring 5.0 + Spring Boot 2.x和Project Reactor等技术开发的网关，旨在为微服务架构提供一种有效的统一的API路由管理方式。  
>   
> Spring Cloud Gateway作为Spring Cloud生态系统中的网关组件，目标是替代Zuul。由于Zuul2.x的多次跳票，为了提升网关的性能，Spring Cloud官方基于Spring WebFlux开发了非阻塞的网关组件Gateway，WebFlux框架底层使用了高性能的Reactor模式的非阻塞通信框架Netty。

## 引入依赖 ##

<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-gateway</artifactId>
    </dependency>

因为要从注册中心对服务实例进行动态路由，这里加入了`eureka-client`的依赖，把`gateway`注册到`eureka`中。

## 服务发现 ##

@SpringBootApplication
    @EnableDiscoveryClient
    public class GatewayApplication { 
        public static void main(String[] args) { 
            SpringApplication.run(GatewayApplication.class, args);
        }
    }

## 编写配置 ##

事前先编写如下2个服务，并提供相应的接口，服务名称分别为`cloud-provider`、`cloud-consumer`  
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![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0UwOTYyMDEyNg_size_16_color_FFFFFF_t_70 1]

server:
      port: 8008
    spring:
      application:
        name: cloud-gateway
      devtools:
        livereload:
          port: 35731 # 设置热部署插件端口，防止端口冲突导致热加载不生效
      cloud:
        gateway:
          discovery:
            locator:
              enabled: true # 开启动态路由，不配置uri时默认访问路径：/serviceId/url, e.g. http://localhost:8008/cloud-provider/provider/xudc
              lower-case-service-id: true # 启用serviceId小写功能，默认是全部大写，e.g. CLOUD-PROVIDER,开启后：cloud-provider
          routes:
            - id: spring-cloud-provider # 指定路由id，可任意名称，唯一即可
              uri: lb://cloud-provider # lb表示负载均衡到<serviceId>
              predicates:
                - Path=/provider/**
    
    eureka:
      client:
        service-url:
          defaultZone: http://localhost:8761/eureka/

## 自定义全局过滤 ##

@Component
    public class CustomFilter implements GlobalFilter, Ordered { 
        /** * 模拟用户登录过滤 * 携带token参数则认为是授权的，未携带则未授权，拒绝访问 * @param exchange * @param chain * @return */
        @Override
        public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) { 
            ServerHttpRequest request = exchange.getRequest();
            String token = request.getQueryParams().getFirst("token");
            if (StringUtils.isEmpty(token)) { 
                ServerHttpResponse response = exchange.getResponse();
                response.setStatusCode(HttpStatus.UNAUTHORIZED);
                byte[] bytes = "{\"status\": 401,\"message\": \"Unauthorized Request!请求未授权\"}".getBytes(StandardCharsets.UTF_8);
                DataBuffer buffer = response.bufferFactory().wrap(bytes);
                // 设置编码utf-8，否则浏览器中文可能会乱码
                response.getHeaders().add("content-type", "text/plain;charset=utf-8");
                // return exchange.getResponse().setComplete();
                return response.writeWith(Flux.just(buffer));
            }
            // 通过则放行
            return chain.filter(exchange);
        }
    
        @Override
        public int getOrder() { 
            return 0;
        }
    }

## 测试 ##

GET http://localhost:8008/provider/cindy
    
    HTTP/1.1 401 Unauthorized
    transfer-encoding: chunked
    content-type: text/plain;charset=utf-8
    
    { "status": 401,"message": "Unauthorized Request!请求未授权"}

GET http://localhost:8008/provider/cindy?token=qwerasd
    
    HTTP/1.1 200 OK
    Content-Type: text/plain;charset=UTF-8
    Content-Length: 12
    
    Hello, cindy

以上就是Spring Cloud Gateway的简单使用。  
更多功能使用，请参阅官方文档: [https://cloud.spring.io/spring-cloud-static/spring-cloud-gateway/2.2.2.RELEASE/reference/html/\#gateway-starter][https_cloud.spring.io_spring-cloud-static_spring-cloud-gateway_2.2.2.RELEASE_reference_html_gateway-starter]

> 因个人能力有限，如果不足或错误之处，欢迎指正~

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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0UwOTYyMDEyNg_size_16_color_FFFFFF_t_70 1]: /images/20230528/b86ed1db6aca4159ba035a7b20f827d9.png
[https_cloud.spring.io_spring-cloud-static_spring-cloud-gateway_2.2.2.RELEASE_reference_html_gateway-starter]: https://cloud.spring.io/spring-cloud-static/spring-cloud-gateway/2.2.2.RELEASE/reference/html/#gateway-starter