• GatewayFilter 工厂
  • AddRequestHeader
  • AddRequestHeadersIfNotPresent
  • AddRequestParameter
  • AddResponseHeader

GatewayFilter 工厂

网关过滤器工厂GatewayFilterFactory 允许以某种方式修改传入的HTTP 请求或返回的HTTP 响应。其作用域是某些特定路由。SpringCloudGateway 包括很多种内置的网关过滤器工厂。下面会学习较常用的几种。

AddRequestHeader

AddRequestHeader GatewayFilter 工厂需要一个 name 和 value 参数。下面的例子配置了一个 AddRequestHeader GatewayFilter。

添加请求头

spring:
  application:
    name: depart-consumer # 微服务名称
  cloud:
    gateway:
      routes:
        - id: add_request_header_route
          uri: http://localhost:8080
          predicates:
            - Path=/**
          filters:
            - AddRequestHeader=X-Request-Color, blue

新建一个服务，端口8080，获取请求头

package com.zjw.controller;

import jakarta.servlet.http.HttpServletRequest;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.Enumeration;

/**
 * @since 2023/11/28 13:41
 */
@RestController
@RequestMapping("/info")
public class ShowInfoController {

    @GetMapping("/header")
    public String getHeader(HttpServletRequest request){
        Enumeration<String> headers = request.getHeaders("X-Request-Color");
        StringBuilder sb = new StringBuilder();
        while (headers.hasMoreElements()) {
            sb.append(headers.nextElement()).append(" ");
        }
        return "X-Request-Color: " + sb.toString();
    }
}

通过api实现增加请求头。

@Configuration
public class GatewayConfig {

    /**
     * 增加请求头
     */
    @Bean
    public RouteLocator addRequestHeader(RouteLocatorBuilder builder) {
        return builder.routes()
                .route("add_request_header_route",
                        r -> r.path("/**")
                                .filters(fs -> fs
                                        .addRequestHeader("X-Request-Color", "blue")
                                        .addRequestHeader("X-Request-Color", "red"))
                                .uri("http://localhost:8080"))
                .build();
    }
}

AddRequestHeadersIfNotPresent

AddRequestHeadersIfNotPresent GatewayFilter 工厂接受一个由冒号分隔的 name 和 value 键值对的集合。下面的例子配置了一个 AddRequestHeadersIfNotPresent GatewayFilter。

spring:
  application:
    name: depart-consumer # 微服务名称
  cloud:
    gateway:
      routes:
        - id: add_request_header_route
          uri: http://localhost:8080
          predicates:
            - Path=/**
          filters:
            - AddRequestHeader=X-Request-Color, blue
            - AddRequestHeadersIfNotPresent=X-Request-Color-1:blue,X-Request-Color-2:green

这个列表为所有匹配的请求在下游请求的header信息中添加了两个header信息 X-Request-Color-1:blue 和 X-Request-Color-2:green。这类似于 AddRequestHeader 的工作方式，但与 AddRequestHeader 不同的是，它只在header 信息不存在的情况下才会这样做。否则，客户端请求中的原始值将被发送。

java写法

@Configuration
public class GatewayConfig {

    /**
     * addRequestHeader增加请求头
     */
    @Bean
    public RouteLocator addRequestHeadersIfNotPresent(RouteLocatorBuilder builder) {
        return builder.routes()
                .route("add_request_header_route",
                        r -> r.path("/**")
                                .filters(fs -> fs
                                        .addRequestHeadersIfNotPresent("X-Request-Color:blue"))
                                .uri("http://localhost:8080"))
                .build();
    }
}

AddRequestParameter

AddRequestParameter GatewayFilter Factory需要一个 name 和 value 参数。下面的例子配置了一个 AddRequestParameter GatewayFilter。

spring:
  application:
    name: depart-consumer # 微服务名称
  cloud:
    gateway:
      routes:
        - id: add_request_parameter_route
          uri: http://localhost:8080
          predicates:
            - Path=/**
          filters:
            - AddRequestParameter=color, blue
            - AddRequestParameter=color, red

java实现

@Configuration
public class GatewayConfig {

    /**
     * addRequestHeader增加请求头
     */
    @Bean
    public RouteLocator addRequestParameter(RouteLocatorBuilder builder) {
        return builder.routes()
                .route("add_request_parameter_route",
                        r -> r.path("/**")
                                .filters(fs -> fs
                                        .addRequestParameter("color","red"))
                                .uri("http://localhost:8080"))
                .build();
    }
}

AddResponseHeader

AddResponseHeader GatewayFilter 工厂需要一个 name 和 value 参数。下面的例子配置了一个 AddResponseHeader GatewayFilter。

spring:
  application:
    name: depart-consumer # 微服务名称
  cloud:
    gateway:
      routes:
        - id: add_response_header_route
          uri: http://localhost:8080
          predicates:
            - Path=/**
          filters:
            - AddResponseHeader=X-Response-Color, Blue

java实现

@Configuration
public class GatewayConfig {

    /**
     * addResponseHeader增加响应头
     */
    @Bean
    public RouteLocator addResponseHeader(RouteLocatorBuilder builder) {
        return builder.routes()
                .route("add_response_header_route",
                        r -> r.path("/**")
                                .filters(fs -> fs
                                        .addResponseHeader("color","red"))
                                .uri("http://localhost:8080"))
                .build();
    }
}