AbstractMessageParser.java revision d42abb2fd917184764daf22f5f299e848b8701d7 
1/*
2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/impl/io/AbstractMessageParser.java $
3 * $Revision: 576077 $
4 * $Date: 2007-09-16 04:50:22 -0700 (Sun, 16 Sep 2007) $
5 *
6 * ====================================================================
7 * Licensed to the Apache Software Foundation (ASF) under one
8 * or more contributor license agreements.  See the NOTICE file
9 * distributed with this work for additional information
10 * regarding copyright ownership.  The ASF licenses this file
11 * to you under the Apache License, Version 2.0 (the
12 * "License"); you may not use this file except in compliance
13 * with the License.  You may obtain a copy of the License at
14 *
15 *   http://www.apache.org/licenses/LICENSE-2.0
16 *
17 * Unless required by applicable law or agreed to in writing,
18 * software distributed under the License is distributed on an
19 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
20 * KIND, either express or implied.  See the License for the
21 * specific language governing permissions and limitations
22 * under the License.
23 * ====================================================================
24 *
25 * This software consists of voluntary contributions made by many
26 * individuals on behalf of the Apache Software Foundation.  For more
27 * information on the Apache Software Foundation, please see
28 * <http://www.apache.org/>.
29 *
30 */
31
32package org.apache.http.impl.io;
33
34import java.io.IOException;
35import java.util.ArrayList;
36
37import org.apache.http.Header;
38import org.apache.http.HttpException;
39import org.apache.http.HttpMessage;
40import org.apache.http.ParseException;
41import org.apache.http.ProtocolException;
42import org.apache.http.io.HttpMessageParser;
43import org.apache.http.io.SessionInputBuffer;
44import org.apache.http.message.LineParser;
45import org.apache.http.message.BasicLineParser;
46import org.apache.http.params.CoreConnectionPNames;
47import org.apache.http.params.HttpParams;
48import org.apache.http.util.CharArrayBuffer;
49
50/**
51 * Message parser base class.
52 *
53 * @author Michael Becke
54 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
55 *
56 * @deprecated Please use {@link java.net.URL#openConnection} instead.
57 *     Please visit <a href="http://android-developers.blogspot.com/2011/09/androids-http-clients.html">this webpage</a>
58 *     for further details.
59 */
60@Deprecated
61public abstract class AbstractMessageParser implements HttpMessageParser {
62
63    private final SessionInputBuffer sessionBuffer;
64    private final int maxHeaderCount;
65    private final int maxLineLen;
66    protected final LineParser lineParser;
67
68
69    public AbstractMessageParser(
70            final SessionInputBuffer buffer,
71            final LineParser parser,
72            final HttpParams params) {
73        super();
74        if (buffer == null) {
75            throw new IllegalArgumentException("Session input buffer may not be null");
76        }
77        if (params == null) {
78            throw new IllegalArgumentException("HTTP parameters may not be null");
79        }
80        this.sessionBuffer = buffer;
81        this.maxHeaderCount = params.getIntParameter(
82                CoreConnectionPNames.MAX_HEADER_COUNT, -1);
83        this.maxLineLen = params.getIntParameter(
84                CoreConnectionPNames.MAX_LINE_LENGTH, -1);
85        this.lineParser = (parser != null) ? parser : BasicLineParser.DEFAULT;
86    }
87
88    /**
89     * Parses HTTP headers from the data receiver stream according to the generic
90     * format as given in Section 3.1 of RFC 822, RFC-2616 Section 4 and 19.3.
91     *
92     * @param inbuffer Session input buffer
93     * @param maxHeaderCount maximum number of headers allowed. If the number
94     *  of headers received from the data stream exceeds maxCount value, an
95     *  IOException will be thrown. Setting this parameter to a negative value
96     *  or zero  will disable the check.
97     * @param maxLineLen maximum number of characters for a header line,
98     *                   including the continuation lines
99     * @return array of HTTP headers
100     *
101     * @throws HttpException
102     * @throws IOException
103     */
104    public static Header[] parseHeaders(
105            final SessionInputBuffer inbuffer,
106            int maxHeaderCount,
107            int maxLineLen,
108            LineParser parser)
109        throws HttpException, IOException {
110
111        if (inbuffer == null) {
112            throw new IllegalArgumentException("Session input buffer may not be null");
113        }
114        if (parser == null)
115            parser = BasicLineParser.DEFAULT;
116
117        ArrayList headerLines = new ArrayList();
118
119        CharArrayBuffer current = null;
120        CharArrayBuffer previous = null;
121        for (;;) {
122            if (current == null) {
123                current = new CharArrayBuffer(64);
124            } else {
125                current.clear();
126            }
127            int l = inbuffer.readLine(current);
128            if (l == -1 || current.length() < 1) {
129                break;
130            }
131            // Parse the header name and value
132            // Check for folded headers first
133            // Detect LWS-char see HTTP/1.0 or HTTP/1.1 Section 2.2
134            // discussion on folded headers
135            if ((current.charAt(0) == ' ' || current.charAt(0) == '\t') && previous != null) {
136                // we have continuation folded header
137                // so append value
138                int i = 0;
139                while (i < current.length()) {
140                    char ch = current.charAt(i);
141                    if (ch != ' ' && ch != '\t') {
142                        break;
143                    }
144                    i++;
145                }
146                if (maxLineLen > 0
147                        && previous.length() + 1 + current.length() - i > maxLineLen) {
148                    throw new IOException("Maximum line length limit exceeded");
149                }
150                previous.append(' ');
151                previous.append(current, i, current.length() - i);
152            } else {
153                headerLines.add(current);
154                previous = current;
155                current = null;
156            }
157            if (maxHeaderCount > 0 && headerLines.size() >= maxHeaderCount) {
158                throw new IOException("Maximum header count exceeded");
159            }
160        }
161        Header[] headers = new Header[headerLines.size()];
162        for (int i = 0; i < headerLines.size(); i++) {
163            CharArrayBuffer buffer = (CharArrayBuffer) headerLines.get(i);
164            try {
165                headers[i] = parser.parseHeader(buffer);
166            } catch (ParseException ex) {
167                throw new ProtocolException(ex.getMessage());
168            }
169        }
170        return headers;
171    }
172
173    protected abstract HttpMessage parseHead(SessionInputBuffer sessionBuffer)
174        throws IOException, HttpException, ParseException;
175
176    public HttpMessage parse() throws IOException, HttpException {
177        HttpMessage message = null;
178        try {
179            message = parseHead(this.sessionBuffer);
180        } catch (ParseException px) {
181            throw new ProtocolException(px.getMessage(), px);
182        }
183        Header[] headers = AbstractMessageParser.parseHeaders(
184                this.sessionBuffer,
185                this.maxHeaderCount,
186                this.maxLineLen,
187                this.lineParser);
188        message.setHeaders(headers);
189        return message;
190    }
191
192}
193