spring.cloud.gateway 说明和使用方式

说明

spring.cloud.gateway 是 SpringCloud 技术栈中的网关组件，提供了基于路由的请求转发、请求限流、服务降级、负载均衡等功能。使用方式如下：

引入依赖

在 SpringBoot 项目中，添加以下依赖：

<dependency>
    <groupId>org.springframework.cloudgroupId>
    <artifactId>spring-cloud-starter-gatewayartifactId>
dependency>

配置路由规则

在项目的配置文件中，配置路由规则，例如：

spring:
  cloud:
    gateway:
      routes:
        - id: order-service
          uri: lb://order-service
          predicates:
            - Path=/api/orders/**
          filters:
            - StripPrefix=1
        - id: user-service
          uri: lb://user-service
          predicates:
            - Path=/api/users/**
          filters:
            - StripPrefix=1

以上配置指定了两个路由规则，分别是 /api/orders/** 和 /api/users/**，路由到 lb://order-service 和 lb://user-service，同时 StripPrefix=1 表示去掉请求路径前缀。

配置过滤器

除了路由规则外，还可以配置过滤器，对请求进行加工处理，例如：

spring:
  cloud:
    gateway:
      routes:
        - id: order-service
          uri: lb://order-service
          predicates:
            - Path=/api/orders/**
          filters:
            - StripPrefix=1
            - name: AuthFilter
              args:
                param: token

以上配置添加了一个名为 AuthFilter 的过滤器，它会检查请求参数中是否包含名为 token 的参数，如果没有则返回 401 错误。

请求限流（Rate Limiting）

请求限流可以限制客户端的请求量，避免服务的过度压力。SpringCloud 中可以使用 Spring Cloud Gateway 、Sentinel 等组件实现请求限流。

在 Spring Cloud Gateway 中，可以使用 Redis 或者内存方式实现请求限流。使用 Redis 需要引入 Redis 和 Lettuce 等依赖，然后在配置文件中开启请求限流功能：

spring:
  cloud:
    gateway:
      routes:
        - id: my-route
          uri: lb://my-service
          predicates:
            - Path=/api/**
          filters:
            - name: RequestRateLimiter
              args:
                redis-rate-limiter.replenishRate: 10
                redis-rate-limiter.burstCapacity: 20

启动应用

完成上述配置后，可以启动应用了。此时，请求进来会先经过网关，然后根据路由规则进行转发。

以上就是 spring.cloud.gateway 的基本说明和使用方式，它可以作为微服务架构中的 API 网关，管理和转发请求，提高应用的性能和稳定性。

Simply put

Explanation

spring.cloud.gateway is a gateway component in the Spring Cloud technology stack, providing features such as route-based request forwarding, request throttling, service degradation, and load balancing. Here’s how to use it:

Add Dependencies

In a Spring Boot project, add the following dependency:

<dependency>
    <groupId>org.springframework.cloudgroupId>
    <artifactId>spring-cloud-starter-gatewayartifactId>
dependency>

Configure Routing Rules

In the project’s configuration file, set up routing rules, for example:

spring:
  cloud:
    gateway:
      routes:
        - id: order-service
          uri: lb://order-service
          predicates:
            - Path=/api/orders/**
          filters:
            - StripPrefix=1
        - id: user-service
          uri: lb://user-service
          predicates:
            - Path=/api/users/**
          filters:
            - StripPrefix=1

The above configuration specifies two routing rules, /api/orders/** and /api/users/** , which route to lb://order-service and lb://user-service , respectively. The StripPrefix=1 means to remove the request path prefix.

Configure Filters

In addition to routing rules, you can also configure filters to process and modify requests, for example:

spring:
  cloud:
    gateway:
      routes:
        - id: order-service
          uri: lb://order-service
          predicates:
            - Path=/api/orders/**
          filters:
            - StripPrefix=1
            - name: AuthFilter
              args:
                param: token

The above configuration adds a filter called AuthFilter , which checks whether the request parameters contain a parameter named token . If not, it returns a 401 error.

Request Rate Limiting

Request rate limiting can limit the number of client requests to avoid excessive pressure on the service. In Spring Cloud, components such as Spring Cloud Gateway and Sentinel can be used to implement request rate limiting.

In Spring Cloud Gateway, you can use Redis or in-memory methods to implement request rate limiting. To use Redis, you need to introduce dependencies such as Redis and Lettuce, and then enable request rate limiting in the configuration file:

spring:
  cloud:
    gateway:
      routes:
        - id: my-route
          uri: lb://my-service
          predicates:
            - Path=/api/**
          filters:
            - name: RequestRateLimiter
              args:
                redis-rate-limiter.replenishRate: 10
                redis-rate-limiter.burstCapacity: 20

Start the Application

After completing the above configuration, you can start the application. At this point, incoming requests will first go through the gateway and then be forwarded according to the routing rules.

The above is a basic explanation and usage of spring.cloud.gateway . It can be used as an API gateway in a microservices architecture to manage and forward requests, improving application performance and stability.