Spring Cloud Gateway网关获取路由转发后的真实地址

在Spring Cloud Gateway中，你可以通过定义一个全局过滤器来获取路由后的实际地址。以下是一个简单的全局过滤器示例，它会记录请求被转发到的实际地址：

import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;
 
import java.net.URI;
 
public class LogForwardedUrlFilter implements GlobalFilter {
 
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
 
        // 打印原始请求的URL
        System.out.println("Original Request URL: " + request.getURI());
 
        // 记录实际转发的地址
        URI originalUri = request.getURI();
        String scheme = originalUri.getScheme();
        String host = originalUri.getHost();
        int port = originalUri.getPort();
        String path = originalUri.getPath();
        String query = originalUri.getQuery();
 
        // 获取转发后的地址
        URI forwardedUrl = URI.create(scheme + "://" + host + (port != -1 ? ":" + port : "") + path + (query != null ? "?" + query : ""));
        System.out.println("Forwarded URL: " + forwardedUrl);
 
        // 继续过滤器链
        return chain.filter(exchange);
    }
}

然后，你需要将这个全局过滤器注册到Spring Cloud Gateway中：

import org.springframework.cloud.gateway.route.RouteLocator;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
 
@Configuration
public class GatewayConfig {
 
    @Bean
    public RouteLocator customRouteLocator(RouteLocatorBuilder builder) {
        return builder.routes()
                .route("path_route", r -> r.path("/get")
                        .filters(f -> f.filter(new LogForwardedUrlFilter()))
                        .uri("http://httpbin.org:80"))
                .build();
    }
}

在这个配置中，当有请求匹配/get路径时，会应用LogForwardedUrlFilter过滤器，并打印出原始请求URL和实际转发的URL。这个例子使用了httpbin.org作为下游服务的地址，你可以根据实际情况修改URI。