如何在 application.yml Spring Cloud Gateway 中指定自定义过滤器

Question

我有一个自定义网关过滤器 MYGatewayFilter.java 文件，现在我想将此网关过滤器与我在 application.yml 中编写的路由一起使用

 spring:
  cloud:
   gateway:
    routes:
      - id: login2_route
      uri: http://127.0.0.1:8083/login
      predicates:
       - Path: /login/
      filters:

我如何为上述路线定义过滤器

自定义过滤器 MyGatewayFilter.java

public class MyGatewayFilter implements GatewayFilter {
    @Override
  public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
      ServerHttpRequest request;
      if(request.getHeaders().get("x-mydata")!=null){
         request= exchange.getRequest().mutate().header("my-new-header",request.getHeaders().get("x-mydata").get(0)).build();
      }

      return chain.filter(exchange.mutate().request(request).build());
  }
}       

Answer 1

你应该实现 GatewayFilterFactory 而不是实现 GatewayFilter

并使其成为组件：

@Component
public class MyGatewayFilter implements GatewayFilterFactory {

然后你可以通过路由中的bean名称来引用它。

filters:
- MyGatewayFilter

目前这方面的文档不是很好。我只能通过查看 github 上 spring-cloud-gateway 的源代码来解决这个问题

Answer 2

你需要实现GatewayFilterFactory

@Component
public class DemoGatewayFilter implements GatewayFilterFactory<DemoGatewayFilter.Config> {

    @Override
    public GatewayFilter apply(Config config) {
        return (exchange, chain) -> {
            System.out.println("gateway filter name "+config.getName());
            return chain.filter(exchange);
        };
    }

    @Override
    public Config newConfig() {
        return new Config("DemoGatewayFilter");
    }

    public static class Config {

        public Config(String name){
            this.name = name;
        }
        private String name;

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }
    }
}

在 application.yml 文件中

 spring:
  application:
  cloud:
    gateway:
      routes:
      - id: MayApplication
        uri: http://myapplication:8080
        predicates:
        - Path=/apipath/to/filter/**
        filters:
          - DemoGatewayFilter

Answer 3

我认为 Spring Cloud Gateway 2.2.1 有一些变化。
我提到了SaveSessionGatewayFilterFactory.java。

@Component
public class DemoGatewayFilter implements AbstractGatewayFilterFactory {

    @Override
    public GatewayFilter apply(Object config) {
        return (exchange, chain) -> {
            return chain.filter(exchange);
        };
/*
it works too
       return new GatewayFilter() {
           @Override
           public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
               return chain.filter(exchange);
           }
       }
*/
    }

}

在 application.yml 文件中

 spring:
  application:
  cloud:
    gateway:
      routes:
      - id: MayApplication
        uri: http://myapplication:8080
        predicates:
        - Path=/api/path/to/filter/**
        filters:
          - DemoGatewayFilter