Spring Cloud Gateway请求转发+过滤

介绍

gateway是Spring Cloud家族中功能强大的网关服务，除了做请求路由之外，还有做到定制化的请求过滤、鉴权等功能，是Spring生态圈基于Java实现的；
做为网关，nginx能做的，它都能做，nginx做不到的，我们也可以通过gateway的过滤器也实现；

项目搭建

引入pom

<!-- spring-boot版本 -->
<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
</parent>
<!-- 网关相关 -->
<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-commons</artifactId>
</dependency>
<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>
<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-webflux</artifactId>
</dependency>
<!-- spring-cloud版本管理器，Greenwich.RELEASE版本 -->
<dependencyManagement>
        <!--spring cloud依赖版本管理-->
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Greenwich.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
</dependencyManagement>

配置yml文件

server:
  port: 9092
spring:
  application:
    name: authing-gateway
  cloud:
    gateway:
      routes:
        - id: service-test
          uri: https://gateway-test.xxxx.com
          predicates:
            - Path=/region/**
      # 跨域配置
      globalcors:
        cors-configurations:
          '[/**]':
            allow-credentials: true
            allowed-origins: "*"
            allowed-headers: "*"
            allowed-methods:
              - OPTIONS
              - GET
              - POST
              - PUT
              - DELETE

过滤器

Gateway有两种过滤器，GateWayFilter路由过滤器，GlobalFilter全局过滤器；下面我们演示添加全局过滤器

import cn.authing.core.auth.AuthenticationClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBuffer;
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.util.CollectionUtils;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.util.List;
import java.util.Map;

/**
 * @Date 2022-04-15
 * @author sxt
 * @describe 检查token是否合法过滤器
 */
@Component
public class TokenCheckFilter implements GlobalFilter, Ordered {

    @Autowired
    private AuthenticationClient authenticationClient;

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();
        // 从请求头中获取token
        List<String> token = request.getHeaders().get("token");
        // token为空，直接返回
        if(CollectionUtils.isEmpty(token)){
            return createError(HttpStatus.UNAUTHORIZED, "token non-existent!", response);
        }
        // 校验token
        try {
            Map<String, Object> execute = (Map<String, Object>)authenticationClient.introspectToken(token.get(0)).execute();
            if(!(boolean) execute.get("active")){
                return createError(HttpStatus.FORBIDDEN, "illegal request!", response);
            }
        } catch (Exception e) {
            return createError(HttpStatus.FORBIDDEN, "illegal request!", response);
        }
        return chain.filter(exchange);
    }

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

    /**
     * 构建错误返回
     * @param status
     * @param msg    msg仅支持英文
     * @return
     */
    private Mono<Void> createError(HttpStatus status, String msg, ServerHttpResponse response){
        response.setStatusCode(status);
        DataBuffer wrap = response.bufferFactory().wrap(msg.getBytes());
        return response.writeWith(Mono.just(wrap));
    }
}