1 /*
2 * Copyright (c) 2005, 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 {@link java.util.Map}<
33 * {@link java.lang.String},{@link java.util.List}<{@link java.lang.String}>>.
34 * The keys are case-insensitive Strings representing the header names and
35 * the value associated with each key is a {@link List}<{@link String}> with one
36 * element for each occurence of the header name in the request or response.
37 * <p>
38 * For example, if a response header instance contains one key "HeaderName" with two values "value1 and value2"
39 * then this object is output as two header lines:
40 * <blockquote><pre>
41 * HeaderName: value1
42 * HeaderName: value2
43 * </blockquote></pre>
44 * <p>
45 * All the normal {@link java.util.Map} methods are provided, but the following
46 * additional convenience methods are most likely to be used:
47 * <ul>
48 * <li>{@link #getFirst(String)} returns a single valued header or the first value of
49 * a multi-valued header.</li>
50 * <li>{@link #add(String,String)} adds the given header value to the list for the given key</li>
51 * <li>{@link #set(String,String)} sets the given header field to the single value given
52 * overwriting any existing values in the value list.
53 * </ul><p>
54 * All methods in this class accept <code>null</code> values for keys and values. However, null
55 * keys will never will be present in HTTP request headers, and will not be output/sent in response headers.
56 * Null values can be represented as either a null entry for the key (i.e. the list is null) or
57 * where the key has a list, but one (or more) of the list's values is null. Null values are output
58 * as a header line containing the key but no associated value.
59 * @since 1.6
60 */
61 public class Headers implements Map<String,List<String>> {
62
63 HashMap<String,List<String>> map;
64
65 public Headers () {map = new HashMap<String,List<String>>(32);}
66
67 /* Normalize the key by converting to following form.
68 * First char upper case, rest lower case.
69 * key is presumed to be ASCII
70 */
71 private String normalize (String key) {
72 if (key == null) {
73 return null;
74 }
75 int len = key.length();
76 if (len == 0) {
77 return key;
78 }
79 char[] b = key.toCharArray();
80 if (b[0] >= 'a' && b[0] <= 'z') {
81 b[0] = (char)(b[0] - ('a' - 'A'));
82 }
83 for (int i=1; i<len; i++) {
84 if (b[i] >= 'A' && b[i] <= 'Z') {
85 b[i] = (char) (b[i] + ('a' - 'A'));
86 }
87 }
88 return new String(b);
89 }
90
91 public int size() {return map.size();}
92
93 public boolean isEmpty() {return map.isEmpty();}
94
95 public boolean containsKey(Object key) {
96 if (key == null) {
97 return false;
98 }
99 if (!(key instanceof String)) {
100 return false;
101 }
102 return map.containsKey (normalize((String)key));
103 }
104
105 public boolean containsValue(Object value) {
106 return map.containsValue(value);
107 }
108
109 public List<String> get(Object key) {
110 return map.get(normalize((String)key));
111 }
112
113 /**
114 * returns the first value from the List of String values
115 * for the given key (if at least one exists).
116 * @param key the key to search for
117 * @return the first string value associated with the key
118 */
119 public String getFirst (String key) {
120 List<String> l = map.get(normalize((String)key));
121 if (l == null) {
122 return null;
123 }
124 return l.get(0);
125 }
126
127 public List<String> put(String key, List<String> value) {
128 return map.put (normalize(key), value);
129 }
130
131 /**
132 * adds the given value to the list of headers
133 * for the given key. If the mapping does not
134 * already exist, then it is created
135 * @param key the header name
136 * @param value the header value to add to the header
137 */
138 public void add (String key, String value) {
139 String k = normalize(key);
140 List<String> l = map.get(k);
141 if (l == null) {
142 l = new LinkedList<String>();
143 map.put(k,l);
144 }
145 l.add (value);
146 }
147
148 /**
149 * sets the given value as the sole header value
150 * for the given key. If the mapping does not
151 * already exist, then it is created
152 * @param key the header name
153 * @param value the header value to set.
154 */
155 public void set (String key, String value) {
156 LinkedList<String> l = new LinkedList<String>();
157 l.add (value);
158 put (key, l);
159 }
160
161
162 public List<String> remove(Object key) {
163 return map.remove(normalize((String)key));
164 }
165
166 public void putAll(Map<? extends String,? extends List<String>> t) {
167 map.putAll (t);
168 }
169
170 public void clear() {map.clear();}
171
172 public Set<String> keySet() {return map.keySet();}
173
174 public Collection<List<String>> values() {return map.values();}
175
176 public Set<Map.Entry<String, List<String>>> entrySet() {
177 return map.entrySet();
178 }
179
180 public boolean equals(Object o) {return map.equals(o);}
181
182 public int hashCode() {return map.hashCode();}
183 }