1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.http.message;
29
30 import java.io.Serializable;
31
32 import org.apache.http.FormattedHeader;
33 import org.apache.http.HeaderElement;
34 import org.apache.http.ParseException;
35 import org.apache.http.util.Args;
36 import org.apache.http.util.CharArrayBuffer;
37
38 /**
39 * This class represents a raw HTTP header whose content is parsed 'on demand'
40 * only when the header value needs to be consumed.
41 *
42 * @since 4.0
43 */
44 public class BufferedHeader implements FormattedHeader, Cloneable, Serializable {
45
46 private static final long serialVersionUID = -2768352615787625448L;
47
48 /**
49 * Header name.
50 */
51 private final String name;
52
53 /**
54 * The buffer containing the entire header line.
55 */
56 private final CharArrayBuffer buffer;
57
58 /**
59 * The beginning of the header value in the buffer
60 */
61 private final int valuePos;
62
63
64 /**
65 * Creates a new header from a buffer.
66 * The name of the header will be parsed immediately,
67 * the value only if it is accessed.
68 *
69 * @param buffer the buffer containing the header to represent
70 *
71 * @throws ParseException in case of a parse error
72 */
73 public BufferedHeader(final CharArrayBuffer buffer)
74 throws ParseException {
75
76 super();
77 Args.notNull(buffer, "Char array buffer");
78 final int colon = buffer.indexOf(':');
79 if (colon == -1) {
80 throw new ParseException
81 ("Invalid header: " + buffer.toString());
82 }
83 final String s = buffer.substringTrimmed(0, colon);
84 if (s.isEmpty()) {
85 throw new ParseException
86 ("Invalid header: " + buffer.toString());
87 }
88 this.buffer = buffer;
89 this.name = s;
90 this.valuePos = colon + 1;
91 }
92
93
94 @Override
95 public String getName() {
96 return this.name;
97 }
98
99 @Override
100 public String getValue() {
101 return this.buffer.substringTrimmed(this.valuePos, this.buffer.length());
102 }
103
104 @Override
105 public HeaderElement[] getElements() throws ParseException {
106 final ParserCursoror.html#ParserCursor">ParserCursor cursor = new ParserCursor(0, this.buffer.length());
107 cursor.updatePos(this.valuePos);
108 return BasicHeaderValueParser.INSTANCE.parseElements(this.buffer, cursor);
109 }
110
111 @Override
112 public int getValuePos() {
113 return this.valuePos;
114 }
115
116 @Override
117 public CharArrayBuffer getBuffer() {
118 return this.buffer;
119 }
120
121 @Override
122 public String toString() {
123 return this.buffer.toString();
124 }
125
126 @Override
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 }