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.protocol;
029
030import java.io.IOException;
031import java.net.InetAddress;
032
033import org.apache.http.HttpConnection;
034import org.apache.http.HttpException;
035import org.apache.http.HttpHost;
036import org.apache.http.HttpInetConnection;
037import org.apache.http.HttpRequest;
038import org.apache.http.HttpRequestInterceptor;
039import org.apache.http.HttpVersion;
040import org.apache.http.ProtocolException;
041import org.apache.http.ProtocolVersion;
042import org.apache.http.annotation.ThreadingBehavior;
043import org.apache.http.annotation.Contract;
044import org.apache.http.util.Args;
045
046/**
047 * RequestTargetHost is responsible for adding {@code Host} header. This
048 * interceptor is required for client side protocol processors.
049 *
050 * @since 4.0
051 */
052@Contract(threading = ThreadingBehavior.IMMUTABLE)
053public class RequestTargetHost implements HttpRequestInterceptor {
054
055    public RequestTargetHost() {
056        super();
057    }
058
059    @Override
060    public void process(final HttpRequest request, final HttpContext context)
061            throws HttpException, IOException {
062        Args.notNull(request, "HTTP request");
063
064        final HttpCoreContext coreContext = HttpCoreContext.adapt(context);
065
066        final ProtocolVersion ver = request.getRequestLine().getProtocolVersion();
067        final String method = request.getRequestLine().getMethod();
068        if (method.equalsIgnoreCase("CONNECT") && ver.lessEquals(HttpVersion.HTTP_1_0)) {
069            return;
070        }
071
072        if (!request.containsHeader(HTTP.TARGET_HOST)) {
073            HttpHost targetHost = coreContext.getTargetHost();
074            if (targetHost == null) {
075                final HttpConnection conn = coreContext.getConnection();
076                if (conn instanceof HttpInetConnection) {
077                    // Populate the context with a default HTTP host based on the
078                    // inet address of the target host
079                    final InetAddress address = ((HttpInetConnection) conn).getRemoteAddress();
080                    final int port = ((HttpInetConnection) conn).getRemotePort();
081                    if (address != null) {
082                        targetHost = new HttpHost(address.getHostName(), port);
083                    }
084                }
085                if (targetHost == null) {
086                    if (ver.lessEquals(HttpVersion.HTTP_1_0)) {
087                        return;
088                    }
089                    throw new ProtocolException("Target host missing");
090                }
091            }
092            request.addHeader(HTTP.TARGET_HOST, targetHost.toHostString());
093        }
094    }
095
096}