简单来说,这是zuul的替代品，现在开撸！

1.1开始新建一个项目，增加依赖

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

1.2 增加配置文件配置

eureka:
  client:
    service-url:
      defaultZone: http://user:user@demo-springcloud-eureka-one:8761/eureka/
  instance:
    prefer-ip-address: true
spring:
  application:
    name: demo-springcloud-gateway
server:
  port: 8800

1.3 增加启动类上的代码

@EnableDiscoveryClient
@SpringBootApplication
public class DemoSpringcloudGatewayApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoSpringcloudGatewayApplication.class, args);
    }
}

1.4 配置路由的规则，两种方式，一种代码形式，一种配置形式

image.png

1.5 一些逻辑配置样例

spring:
  cloud:
    gateway:
      #可以根据请求参数,cookie,host,请求时间,请求头等进行校验判断路由, 下面根据先后顺序转发
      routes:
        - id: host_route
          uri: http://localhost:8866/
          predicates:
            - Path=/order/** # 请求地址携带order的,则转发
        - id: host_route
          uri: http://localhost:8866/get
          predicates:
            - Host=**.csdn.** # 请求域名携带csdn的,则转发
        - id: query_route
          uri: http://localhost:8866/get
          predicates:
            - Query=username, zzz* # 请求参数含有username,且值满足zzz开头的,则转发(对值的匹配可以省略)
        - id: header_route
          uri: http://localhost:8866/get
          predicates:
            - Header=request, \d+ # 如果请求头含有request,且为数字,则转发
        - id: cookie_route
          uri: http://localhost:8866/get
          predicates:
            - Cookie=name, zzzgd # 如果携带cookie,参数名为name,值为zzzgd,则转发
        - id: path_route
          uri: http://localhost:8866/get
          predicates:
            - Path=/zzzgd/** # 请求地址携带zzzgd的,则转发
        # 路由到其他服务,url需要用[lb://]+[serviceId]
        - id: service_client
          uri: lb://service-client
          predicates:
            - Path=/api-a/** # 如果请求地址满足/api-a/**,则转发到 service-client 服务
          filters:
            - StripPrefix=1 # 去除请求地址中的to_client
        - id: after_route
          uri: http://localhost:8866/get
          predicates:
            - After=2019-03-01T17:42:47.789-07:00[America/Denver] # 如果请求时间大于该时间,则转发

1.6 代码配置形式举例

 @Bean
    public RouteLocator myRoutes(RouteLocatorBuilder builder) {
        return builder.routes()
                .route(p -> p
                        .path("/zuul")
                        .filters(f -> f.addRequestHeader("Hello", "lemon"))
                        .uri("http://localhost:8866/"))
                .build();
    }

 @Bean
    public RouteLocator myRoutes(RouteLocatorBuilder builder) {
        return builder.routes()
                .route(p -> p
                        .path("/get")
                        .filters(f -> f.addRequestHeader("Hello", "World"))
                        .uri(" http://localhost:8866"))
                .route(p -> p
                        .host("*.lemon.com")
                        .filters(f -> f.hystrix(config -> config
                                .setName("test")
                                .setFallbackUri("forward:/fallback")))
                        .uri(" http://localhost:8866"))
                .build();
    }