Spring Cloud GateWay 帮我们内置了很多 Predicates功能，实现了各种路由匹配规
则（通过 Header、请求参数等作为条件）匹配到对应的路由

1 时间点后匹配 

server:
  port: 8888
spring:
  application:
    name: gateway-service
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: consumer
          uri: https://consumer-service
          predicates:
            - After=2023-03-18T17:42:47.789-07:00[America/Denver]

2 时间点前匹配 

server:
  port: 8888
spring:
  application:
    name: gateway-service
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: consumer
          uri: https://consumer-service
          predicates:
            - Before=2025-03-18T17:42:47.789+08:00[Asia/Shanghai]

3 时间区间匹配

server:
  port: 8888
spring:
  application:
    name: gateway-service
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: consumer
          uri: https://consumer-service
          predicates:
            - Between=2022-03-18T17:42:47.789+08:00[Asia/Shanghai],2025-03-18T17:42:47.789+08:00[Asia/Shanghai]

4 指定Cookie正则匹配指定值

这个配置的含义是当接收到的请求中包含名为 sessionId 的 Cookie，且其值匹配正则表达式 \d+（表示任意数字）时，该请求将被路由到 http://example.org。换句话说，这个规则会筛选出带有特定 Cookie 值的请求，并将其转发到指定的 URI。

server:
  port: 8888
spring:
  application:
    name: gateway-service
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: consumer
          uri: https://consumer-service
          predicates:
            - Cookie=sessionId, \d+

5 指定Header正则匹配指定值

这个配置指定了一个名为 consumer 的路由，它将请求转发到 https://consumer-service 服务上。该路由的谓词条件是请求头中的 requestinfo 的值必须是一个数字。

server:
  port: 8888
spring:
  application:
    name: gateway-service
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: consumer
          uri: https://consumer-service
          predicates:
            - Header=requestinfo, \d+

6 请求Host匹配指定值

这个配置定义了一个名为 consumer 的路由，它将请求转发到 https://consumer-service 服务上。该路由的谓词条件是请求的 Host 头必须匹配 **.consumer-service.** 的正则表达式模式。

server:
  port: 8888
spring:
  application:
    name: gateway-service
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: consumer
          uri: https://consumer-service
          predicates:
            - Host=**.consumer-service.**

7 请求Method匹配指定请求方式

指定请求类型是get 或者让post请求

server:
  port: 8888
spring:
  application:
    name: gateway-service
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: consumer
          uri: https://consumer-service
          predicates:
            - Method=GET,POST

8 请求路径正则匹配

这个配置中的 Path=/consumer-service/** 表示当请求的路径以 /consumer-service/ 开头时，将请求转发到 https://consumer-service 服务上

server:
  port: 8888
spring:
  application:
    name: gateway-service
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: consumer
          uri: https://consumer-service
          predicates:
            - Path=/consumer-service/**

9 请求包含某参数

在这个配置中，使用了 Query 谓词来匹配请求中的查询参数。具体来说，Query=name 表示只有请求中带有名为 name 的查询参数时，该路由规则才会被匹配。这意味着只有符合该条件的请求会被转发到 https://consumer-service 服务。

server:
  port: 8888
spring:
  application:
    name: gateway-service
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: consumer
          uri: https://consumer-service
          predicates:
            - Query=name

10 远程地址匹配

在这个配置中，使用了 RemoteAddr 谓词来匹配请求的远程地址。具体来说，RemoteAddr=http://192.168.201.116 表示只有来自远程地址为 192.168.201.116 的请求才会被匹配到该路由规则。这意味着只有符合该条件的请求会被转发到 https://consumer-service 服务。

server:
  port: 8888
spring:
  application:
    name: gateway-service
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: consumer
          uri: https://consumer-service
          predicates:
            - RemoteAddr=192.168.201.116