org.springframework.cloud.gateway.handler.NettyRoutingWebHandler.java Source code

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Here is the source code for org.springframework.cloud.gateway.handler.NettyRoutingWebHandler.java

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/*
 * Copyright 2013-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.springframework.cloud.gateway.handler;

import java.net.URI;
import java.util.Optional;

import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebHandler;

import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.CLIENT_RESPONSE_ATTR;
import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR;

import io.netty.buffer.Unpooled;
import io.netty.handler.codec.http.DefaultHttpHeaders;
import io.netty.handler.codec.http.HttpMethod;
import reactor.core.publisher.Mono;
import reactor.ipc.netty.NettyPipeline;
import reactor.ipc.netty.http.client.HttpClient;

/**
 * @author Spencer Gibb
 */
public class NettyRoutingWebHandler implements WebHandler {

    private final HttpClient httpClient;

    public NettyRoutingWebHandler(HttpClient httpClient) {
        this.httpClient = httpClient;
    }

    @Override
    public Mono<Void> handle(ServerWebExchange exchange) {
        Optional<URI> requestUrl = exchange.getAttribute(GATEWAY_REQUEST_URL_ATTR);
        ServerHttpRequest request = exchange.getRequest();

        final HttpMethod method = HttpMethod.valueOf(request.getMethod().toString());
        final String url = requestUrl.get().toString();

        final DefaultHttpHeaders httpHeaders = new DefaultHttpHeaders();
        request.getHeaders().forEach(httpHeaders::set);

        return this.httpClient.request(method, url,
                req -> req.options(NettyPipeline.SendOptions::flushOnEach).headers(httpHeaders).sendHeaders()
                        .send(request.getBody().map(DataBuffer::asByteBuffer).map(Unpooled::wrappedBuffer)))
                .then(res -> {
                    // Defer committing the response until all route filters have run
                    // Put client response as ServerWebExchange attribute and write response later WriteResponseFilter
                    exchange.getAttributes().put(CLIENT_RESPONSE_ATTR, res);

                    ServerHttpResponse response = exchange.getResponse();
                    // put headers and status so filters can modify the response
                    final HttpHeaders headers = new HttpHeaders();
                    res.responseHeaders().forEach(entry -> headers.add(entry.getKey(), entry.getValue()));

                    response.getHeaders().putAll(headers);
                    response.setStatusCode(HttpStatus.valueOf(res.status().code()));

                    return Mono.empty();
                });
    }
}