1/*
2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/message/BufferedHeader.java $
3 * $Revision: 604625 $
4 * $Date: 2007-12-16 06:11:11 -0800 (Sun, 16 Dec 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.message;
33
34import org.apache.http.FormattedHeader;
35import org.apache.http.HeaderElement;
36import org.apache.http.ParseException;
37import org.apache.http.util.CharArrayBuffer;
38
39/**
40 * This class represents a raw HTTP header whose content is parsed 'on demand'
41 * only when the header value needs to be consumed.
42 *
43 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
44 *
45 *
46 * <!-- empty lines above to avoid 'svn diff' context problems -->
47 * @version $Revision: 604625 $ $Date: 2007-12-16 06:11:11 -0800 (Sun, 16 Dec 2007) $
48 */
49public class BufferedHeader implements FormattedHeader, Cloneable {
50
51    /**
52     * Header name.
53     */
54    private final String name;
55
56    /**
57     * The buffer containing the entire header line.
58     */
59    private final CharArrayBuffer buffer;
60
61    /**
62     * The beginning of the header value in the buffer
63     */
64    private final int valuePos;
65
66
67    /**
68     * Creates a new header from a buffer.
69     * The name of the header will be parsed immediately,
70     * the value only if it is accessed.
71     *
72     * @param buffer    the buffer containing the header to represent
73     *
74     * @throws ParseException   in case of a parse error
75     */
76    public BufferedHeader(final CharArrayBuffer buffer)
77        throws ParseException {
78
79        super();
80        if (buffer == null) {
81            throw new IllegalArgumentException
82                ("Char array buffer may not be null");
83        }
84        int colon = buffer.indexOf(':');
85        if (colon == -1) {
86            throw new ParseException
87                ("Invalid header: " + buffer.toString());
88        }
89        String s = buffer.substringTrimmed(0, colon);
90        if (s.length() == 0) {
91            throw new ParseException
92                ("Invalid header: " + buffer.toString());
93        }
94        this.buffer = buffer;
95        this.name = s;
96        this.valuePos = colon + 1;
97    }
98
99
100    public String getName() {
101        return this.name;
102    }
103
104    public String getValue() {
105        return this.buffer.substringTrimmed(this.valuePos, this.buffer.length());
106    }
107
108    public HeaderElement[] getElements() throws ParseException {
109        ParserCursor cursor = new ParserCursor(0, this.buffer.length());
110        cursor.updatePos(this.valuePos);
111        return BasicHeaderValueParser.DEFAULT
112            .parseElements(this.buffer, cursor);
113    }
114
115    public int getValuePos() {
116        return this.valuePos;
117    }
118
119    public CharArrayBuffer getBuffer() {
120        return this.buffer;
121    }
122
123    public String toString() {
124        return this.buffer.toString();
125    }
126
127    public Object clone() throws CloneNotSupportedException {
128        // buffer is considered immutable
129        // no need to make a copy of it
130        return super.clone();
131    }
132
133}
134