spring cloud gateway網關處理跨域

首先,gateway中不能引入web的依賴:

在網上找到的跨域配置如下:

package com.wm.blog_gateway.config;

import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.cloud.gateway.discovery.DiscoveryClientRouteDefinitionLocator;
import org.springframework.cloud.gateway.discovery.DiscoveryLocatorProperties;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.cloud.gateway.filter.NettyWriteResponseFilter;
import org.springframework.cloud.gateway.route.RouteDefinitionLocator;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.cors.reactive.CorsUtils;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebFilter;
import org.springframework.web.server.WebFilterChain;
import reactor.core.publisher.Mono;

import java.util.ArrayList;


/**
 * 跨域處理,線上使用nginx替代
 */
@Configuration
public class CorsConfig implements GlobalFilter, Ordered {
    private static final String ALL = "*";
    private static final String MAX_AGE = "18000L";

    @Bean
    public RouteDefinitionLocator discoveryClientRouteDefinitionLocator(DiscoveryClient discoveryClient,
                                                                        DiscoveryLocatorProperties properties) {
        return new DiscoveryClientRouteDefinitionLocator(discoveryClient, properties);
    }

   //添加請求頭　
    @Bean
    public WebFilter corsFilter() {
        return (ServerWebExchange ctx, WebFilterChain chain) -> {
            ServerHttpRequest request = ctx.getRequest();
            if (!CorsUtils.isCorsRequest(request)) {
                return chain.filter(ctx);
            }
            HttpHeaders requestHeaders = request.getHeaders();
            ServerHttpResponse response = ctx.getResponse();
            HttpMethod requestMethod = requestHeaders.getAccessControlRequestMethod();
            HttpHeaders headers = response.getHeaders();
            headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_ORIGIN, requestHeaders.getOrigin());
            headers.addAll(HttpHeaders.ACCESS_CONTROL_ALLOW_HEADERS, requestHeaders.getAccessControlRequestHeaders());
            if (requestMethod != null) {
                headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_METHODS, requestMethod.name());
            }
            headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_CREDENTIALS, "true");
            headers.add(HttpHeaders.ACCESS_CONTROL_EXPOSE_HEADERS, ALL);
            headers.add(HttpHeaders.ACCESS_CONTROL_MAX_AGE, MAX_AGE);
            if (request.getMethod() == HttpMethod.OPTIONS) {
                response.setStatusCode(HttpStatus.OK);
                return Mono.empty();
            }
            return chain.filter(ctx);
        };
    }



    @Override
    public int getOrder() {
        // 指定此過濾器位於NettyWriteResponseFilter之後
        // 即待處理完響應體後接着處理響應頭
        return NettyWriteResponseFilter.WRITE_RESPONSE_FILTER_ORDER + 1;
    }
}

但是請求會報錯,重複設置了

Access-Control-Allow-Origin

大部分說是nginx/前端設置了跨域,但是爲並沒有配置nginx,同時前端也沒有設置跨域處理,原因是spring boot 2.1.x 以上的版本會有一個bug

我使用的gateway版本是2.2.1的,需要增加一個配置,過濾掉一些配置,如下:

 //將請求頭中有多個值的去掉 這是該版本的一個bug,否則一直報錯跨域設置重複了 TODO 這是需要特別注意的點
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        return chain.filter(exchange).then(Mono.defer(() -> {
            exchange.getResponse().getHeaders().entrySet().stream()
                    .filter(kv -> (kv.getValue() != null && kv.getValue().size() > 1))
                    .filter(kv -> (kv.getKey().equals(HttpHeaders.ACCESS_CONTROL_ALLOW_ORIGIN)
                            || kv.getKey().equals(HttpHeaders.ACCESS_CONTROL_ALLOW_CREDENTIALS)))
                    .forEach(kv -> {
                        kv.setValue(new ArrayList<String>() {{
                            add(kv.getValue().get(0));
                        }});
                    });

            return chain.filter(exchange);
        }));
    }

 

完整的類如下:

package com.wm.blog_gateway.config;

import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.cloud.gateway.discovery.DiscoveryClientRouteDefinitionLocator;
import org.springframework.cloud.gateway.discovery.DiscoveryLocatorProperties;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.cloud.gateway.filter.NettyWriteResponseFilter;
import org.springframework.cloud.gateway.route.RouteDefinitionLocator;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.cors.reactive.CorsUtils;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebFilter;
import org.springframework.web.server.WebFilterChain;
import reactor.core.publisher.Mono;

import java.util.ArrayList;


/**
 * 跨域處理,線上使用nginx替代
 */
@Configuration
public class CorsConfig implements GlobalFilter, Ordered {
    private static final String ALL = "*";
    private static final String MAX_AGE = "18000L";

    @Bean
    public RouteDefinitionLocator discoveryClientRouteDefinitionLocator(DiscoveryClient discoveryClient,
                                                                        DiscoveryLocatorProperties properties) {
        return new DiscoveryClientRouteDefinitionLocator(discoveryClient, properties);
    }

   //添加請求頭　
    @Bean
    public WebFilter corsFilter() {
        return (ServerWebExchange ctx, WebFilterChain chain) -> {
            ServerHttpRequest request = ctx.getRequest();
            if (!CorsUtils.isCorsRequest(request)) {
                return chain.filter(ctx);
            }
            HttpHeaders requestHeaders = request.getHeaders();
            ServerHttpResponse response = ctx.getResponse();
            HttpMethod requestMethod = requestHeaders.getAccessControlRequestMethod();
            HttpHeaders headers = response.getHeaders();
            headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_ORIGIN, requestHeaders.getOrigin());
            headers.addAll(HttpHeaders.ACCESS_CONTROL_ALLOW_HEADERS, requestHeaders.getAccessControlRequestHeaders());
            if (requestMethod != null) {
                headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_METHODS, requestMethod.name());
            }
            headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_CREDENTIALS, "true");
            headers.add(HttpHeaders.ACCESS_CONTROL_EXPOSE_HEADERS, ALL);
            headers.add(HttpHeaders.ACCESS_CONTROL_MAX_AGE, MAX_AGE);
            if (request.getMethod() == HttpMethod.OPTIONS) {
                response.setStatusCode(HttpStatus.OK);
                return Mono.empty();
            }
            return chain.filter(ctx);
        };
    }


   //將請求頭中有多個值的去掉 這是該版本的一個bug,否則一直報錯跨域設置重複了 TODO 這是需要特別注意的點
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        return chain.filter(exchange).then(Mono.defer(() -> {
            exchange.getResponse().getHeaders().entrySet().stream()
                    .filter(kv -> (kv.getValue() != null && kv.getValue().size() > 1))
                    .filter(kv -> (kv.getKey().equals(HttpHeaders.ACCESS_CONTROL_ALLOW_ORIGIN)
                            || kv.getKey().equals(HttpHeaders.ACCESS_CONTROL_ALLOW_CREDENTIALS)))
                    .forEach(kv -> {
                        kv.setValue(new ArrayList<String>() {{
                            add(kv.getValue().get(0));
                        }});
                    });

            return chain.filter(exchange);
        }));
    }

    @Override
    public int getOrder() {
        // 指定此過濾器位於NettyWriteResponseFilter之後
        // 即待處理完響應體後接着處理響應頭
        return NettyWriteResponseFilter.WRITE_RESPONSE_FILTER_ORDER + 1;
    }
}

測試解決