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;
031
032import org.apache.http.Header;
033import org.apache.http.HttpEntity;
034import org.apache.http.HttpException;
035import org.apache.http.HttpRequest;
036import org.apache.http.HttpResponse;
037import org.apache.http.HttpResponseInterceptor;
038import org.apache.http.HttpStatus;
039import org.apache.http.HttpVersion;
040import org.apache.http.ProtocolVersion;
041import org.apache.http.annotation.ThreadingBehavior;
042import org.apache.http.annotation.Contract;
043import org.apache.http.util.Args;
044
045/**
046 * ResponseConnControl is responsible for adding {@code Connection} header
047 * to the outgoing responses, which is essential for managing persistence of
048 * {@code HTTP/1.0} connections. This interceptor is recommended for
049 * server side protocol processors.
050 *
051 * @since 4.0
052 */
053@Contract(threading = ThreadingBehavior.IMMUTABLE)
054public class ResponseConnControl implements HttpResponseInterceptor {
055
056    public ResponseConnControl() {
057        super();
058    }
059
060    @Override
061    public void process(final HttpResponse response, final HttpContext context)
062            throws HttpException, IOException {
063        Args.notNull(response, "HTTP response");
064
065        final HttpCoreContext corecontext = HttpCoreContext.adapt(context);
066
067        // Always drop connection after certain type of responses
068        final int status = response.getStatusLine().getStatusCode();
069        if (status == HttpStatus.SC_BAD_REQUEST ||
070                status == HttpStatus.SC_REQUEST_TIMEOUT ||
071                status == HttpStatus.SC_LENGTH_REQUIRED ||
072                status == HttpStatus.SC_REQUEST_TOO_LONG ||
073                status == HttpStatus.SC_REQUEST_URI_TOO_LONG ||
074                status == HttpStatus.SC_SERVICE_UNAVAILABLE ||
075                status == HttpStatus.SC_NOT_IMPLEMENTED) {
076            response.setHeader(HTTP.CONN_DIRECTIVE, HTTP.CONN_CLOSE);
077            return;
078        }
079        final Header explicit = response.getFirstHeader(HTTP.CONN_DIRECTIVE);
080        if (explicit != null && HTTP.CONN_CLOSE.equalsIgnoreCase(explicit.getValue())) {
081            // Connection persistence explicitly disabled
082            return;
083        }
084        // Always drop connection for HTTP/1.0 responses and below
085        // if the content body cannot be correctly delimited
086        final HttpEntity entity = response.getEntity();
087        if (entity != null) {
088            final ProtocolVersion ver = response.getStatusLine().getProtocolVersion();
089            if (entity.getContentLength() < 0 &&
090                    (!entity.isChunked() || ver.lessEquals(HttpVersion.HTTP_1_0))) {
091                response.setHeader(HTTP.CONN_DIRECTIVE, HTTP.CONN_CLOSE);
092                return;
093            }
094        }
095        // Drop connection if requested by the client or request was <= 1.0
096        final HttpRequest request = corecontext.getRequest();
097        if (request != null) {
098            final Header header = request.getFirstHeader(HTTP.CONN_DIRECTIVE);
099            if (header != null) {
100                response.setHeader(HTTP.CONN_DIRECTIVE, header.getValue());
101            } else if (request.getProtocolVersion().lessEquals(HttpVersion.HTTP_1_0)) {
102                response.setHeader(HTTP.CONN_DIRECTIVE, HTTP.CONN_CLOSE);
103            }
104        }
105    }
106
107}