001/*
002 * ====================================================================
003 * Licensed to the Apache Software Foundation (ASF) under one
004 * or more contributor license agreements.  See the NOTICE file
005 * distributed with this work for additional information
006 * regarding copyright ownership.  The ASF licenses this file
007 * to you under the Apache License, Version 2.0 (the
008 * "License"); you may not use this file except in compliance
009 * with the License.  You may obtain a copy of the License at
010 *
011 *   http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing,
014 * software distributed under the License is distributed on an
015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
016 * KIND, either express or implied.  See the License for the
017 * specific language governing permissions and limitations
018 * under the License.
019 * ====================================================================
020 *
021 * This software consists of voluntary contributions made by many
022 * individuals on behalf of the Apache Software Foundation.  For more
023 * information on the Apache Software Foundation, please see
024 * <http://www.apache.org/>.
025 *
026 */
027
028package org.apache.http.client.protocol;
029
030import java.io.IOException;
031
032import org.apache.commons.logging.Log;
033import org.apache.commons.logging.LogFactory;
034import org.apache.http.HttpException;
035import org.apache.http.HttpRequest;
036import org.apache.http.HttpRequestInterceptor;
037import org.apache.http.annotation.Contract;
038import org.apache.http.annotation.ThreadingBehavior;
039import org.apache.http.conn.routing.RouteInfo;
040import org.apache.http.protocol.HTTP;
041import org.apache.http.protocol.HttpContext;
042import org.apache.http.util.Args;
043
044/**
045 * This protocol interceptor is responsible for adding {@code Connection}
046 * or {@code Proxy-Connection} headers to the outgoing requests, which
047 * is essential for managing persistence of {@code HTTP/1.0} connections.
048 *
049 * @since 4.0
050 */
051@Contract(threading = ThreadingBehavior.IMMUTABLE)
052public class RequestClientConnControl implements HttpRequestInterceptor {
053
054    private final Log log = LogFactory.getLog(getClass());
055
056    private static final String PROXY_CONN_DIRECTIVE = "Proxy-Connection";
057
058    public RequestClientConnControl() {
059        super();
060    }
061
062    @Override
063    public void process(final HttpRequest request, final HttpContext context)
064            throws HttpException, IOException {
065        Args.notNull(request, "HTTP request");
066
067        final String method = request.getRequestLine().getMethod();
068        if (method.equalsIgnoreCase("CONNECT")) {
069            request.setHeader(PROXY_CONN_DIRECTIVE, HTTP.CONN_KEEP_ALIVE);
070            return;
071        }
072
073        final HttpClientContext clientContext = HttpClientContext.adapt(context);
074
075        // Obtain the client connection (required)
076        final RouteInfo route = clientContext.getHttpRoute();
077        if (route == null) {
078            this.log.debug("Connection route not set in the context");
079            return;
080        }
081
082        if (route.getHopCount() == 1 || route.isTunnelled()) {
083            if (!request.containsHeader(HTTP.CONN_DIRECTIVE)) {
084                request.addHeader(HTTP.CONN_DIRECTIVE, HTTP.CONN_KEEP_ALIVE);
085            }
086        }
087        if (route.getHopCount() == 2 && !route.isTunnelled()) {
088            if (!request.containsHeader(PROXY_CONN_DIRECTIVE)) {
089                request.addHeader(PROXY_CONN_DIRECTIVE, HTTP.CONN_KEEP_ALIVE);
090            }
091        }
092    }
093
094}