引入依赖

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>${spring-cloud.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

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

自定义过滤器

可以继承 AbstractGatewayFilterFactory 或实现 GlobalFilter 实现过滤请求功能

GatewayFilter

GatewayFilter 只能指定路径上应用

import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;

@Component
public class AuthGatewayFilterFactory extends AbstractGatewayFilterFactory<AuthGatewayFilterFactory.Config> {

    public AuthGatewayFilterFactory() {
        super(Config.class);
    }

    @Override
    public GatewayFilter apply(Config config) {
        return (exchange, chain) -> {
            System.out.println("Welcome to AuthFilter.");
            String token = exchange.getRequest().getHeaders().getFirst("sign");
            if (Config.secret.equals(token)) {
                return chain.filter(exchange);
            }
            ServerHttpResponse response = exchange.getResponse();
            response.setStatusCode(HttpStatus.UNAUTHORIZED);
            return response.setComplete();
        };
    }

    static class Config {
        static String secret = "1234";
    }
}

spring:
  cloud:
    gateway:
      routes:
      - id: service2_route
        uri: http://127.0.0.1:8082
        predicates:
        - Path=/s2/**
        filters:
        - StripPrefix=1 # 去掉路径的 n 个前缀
        - Auth=true # 输入过滤器类的名称前缀

GlobalFilter

GlobalFilter 可以在全局应用

import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

@Component
public class AuthGlobalFilter implements GlobalFilter, Ordered {
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        System.out.println("Welcome to AuthGlobalFilter.");
        ServerHttpRequest request = exchange.getRequest();
        String sign = request.getHeaders().get("sign").get(0);
        String token = "1234";
        if(token.equals(sign)) {
            return chain.filter(exchange);
        }
        ServerHttpResponse response = exchange.getResponse();
        response.setStatusCode(HttpStatus.UNAUTHORIZED);
        return response.setComplete();
    }

    @Override
    public int getOrder() {
        return 0;
    }
}