1 /*
2 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.net.httpserver;
27
28 import java.util.*;
29
30 /**
31 * HTTP request and response headers are represented by this class which implements
32 * the interface
33 * {@link java.util.Map}{@literal <}{@link java.lang.String}, {@link java.util.List}
34 * {@literal <}{@link java.lang.String}{@literal >>}.
35 * The keys are case-insensitive Strings representing the header names and
36 * the value associated with each key is
37 * a {@link List}{@literal <}{@link String}{@literal >} with one
38 * element for each occurrence of the header name in the request or response.
39 * <p>
40 * For example, if a response header instance contains
41 * one key "HeaderName" with two values "value1 and value2"
42 * then this object is output as two header lines:
43 * <blockquote><pre>
44 * HeaderName: value1
45 * HeaderName: value2
46 * </pre></blockquote>
47 * <p>
48 * All the normal {@link java.util.Map} methods are provided, but the following
49 * additional convenience methods are most likely to be used:
50 * <ul>
51 * <li>{@link #getFirst(String)} returns a single valued header or the first value of
52 * a multi-valued header.</li>
53 * <li>{@link #add(String,String)} adds the given header value to the list for the given key</li>
54 * <li>{@link #set(String,String)} sets the given header field to the single value given
55 * overwriting any existing values in the value list.
56 * </ul><p>
57 * All methods in this class accept <code>null</code> values for keys and values. However, null
58 * keys will never will be present in HTTP request headers, and will not be output/sent in response headers.
59 * Null values can be represented as either a null entry for the key (i.e. the list is null) or
60 * where the key has a list, but one (or more) of the list's values is null. Null values are output
61 * as a header line containing the key but no associated value.
62 * @since 1.6
63 */
64 public class Headers implements Map<String,List<String>> {
65
66 HashMap<String,List<String>> map;
67
68 public Headers () {map = new HashMap<String,List<String>>(32);}
69
70 /* Normalize the key by converting to following form.
71 * First char upper case, rest lower case.
72 * key is presumed to be ASCII
73 */
74 private String normalize (String key) {
75 if (key == null) {
76 return null;
77 }
78 int len = key.length();
79 if (len == 0) {
80 return key;
81 }
82 char[] b = key.toCharArray();
83 if (b[0] >= 'a' && b[0] <= 'z') {
84 b[0] = (char)(b[0] - ('a' - 'A'));
85 } else if (b[0] == '\r' || b[0] == '\n')
86 throw new IllegalArgumentException("illegal character in key");
87
88 for (int i=1; i<len; i++) {
89 if (b[i] >= 'A' && b[i] <= 'Z') {
90 b[i] = (char) (b[i] + ('a' - 'A'));
91 } else if (b[i] == '\r' || b[i] == '\n')
92 throw new IllegalArgumentException("illegal character in key");
93 }
94 return new String(b);
95 }
96
97 public int size() {return map.size();}
98
99 public boolean isEmpty() {return map.isEmpty();}
100
101 public boolean containsKey(Object key) {
102 if (key == null) {
103 return false;
104 }
105 if (!(key instanceof String)) {
106 return false;
107 }
108 return map.containsKey (normalize((String)key));
109 }
110
111 public boolean containsValue(Object value) {
112 return map.containsValue(value);
113 }
114
115 public List<String> get(Object key) {
116 return map.get(normalize((String)key));
117 }
118
119 /**
120 * returns the first value from the List of String values
121 * for the given key (if at least one exists).
122 * @param key the key to search for
123 * @return the first string value associated with the key
124 */
125 public String getFirst (String key) {
126 List<String> l = map.get(normalize(key));
127 if (l == null) {
128 return null;
129 }
130 return l.get(0);
131 }
132
133 public List<String> put(String key, List<String> value) {
134 for (String v : value)
135 checkValue(v);
136 return map.put (normalize(key), value);
137 }
138
139 /**
140 * adds the given value to the list of headers
141 * for the given key. If the mapping does not
142 * already exist, then it is created
143 * @param key the header name
144 * @param value the header value to add to the header
145 */
146 public void add (String key, String value) {
147 checkValue(value);
148 String k = normalize(key);
149 List<String> l = map.get(k);
150 if (l == null) {
151 l = new LinkedList<String>();
152 map.put(k,l);
153 }
154 l.add (value);
155 }
156
157 private static void checkValue(String value) {
158 int len = value.length();
159 for (int i=0; i<len; i++) {
160 char c = value.charAt(i);
161 if (c == '\r') {
162 // is allowed if it is followed by \n and a whitespace char
163 if (i >= len - 2) {
164 throw new IllegalArgumentException("Illegal CR found in header");
165 }
166 char c1 = value.charAt(i+1);
167 char c2 = value.charAt(i+2);
168 if (c1 != '\n') {
169 throw new IllegalArgumentException("Illegal char found after CR in header");
170 }
171 if (c2 != ' ' && c2 != '\t') {
172 throw new IllegalArgumentException("No whitespace found after CRLF in header");
173 }
174 i+=2;
175 } else if (c == '\n') {
176 throw new IllegalArgumentException("Illegal LF found in header");
177 }
178 }
179 }
180
181 /**
182 * sets the given value as the sole header value
183 * for the given key. If the mapping does not
184 * already exist, then it is created
185 * @param key the header name
186 * @param value the header value to set.
187 */
188 public void set (String key, String value) {
189 LinkedList<String> l = new LinkedList<String>();
190 l.add (value);
191 put (key, l);
192 }
193
194
195 public List<String> remove(Object key) {
196 return map.remove(normalize((String)key));
197 }
198
199 public void putAll(Map<? extends String,? extends List<String>> t) {
200 map.putAll (t);
201 }
202
203 public void clear() {map.clear();}
204
205 public Set<String> keySet() {return map.keySet();}
206
207 public Collection<List<String>> values() {return map.values();}
208
209 public Set<Map.Entry<String, List<String>>> entrySet() {
210 return map.entrySet();
211 }
212
213 public boolean equals(Object o) {return map.equals(o);}
214
215 public int hashCode() {return map.hashCode();}
216 }