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 import java.io.*;
30
31 /**
32 * HTTP request and response headers are represented by this class which implements
33 * the interface {@link java.util.Map}<
34 * {@link java.lang.String},{@link java.util.List}<{@link java.lang.String}>>.
35 * The keys are case-insensitive Strings representing the header names and
36 * the value associated with each key is a {@link List}<{@link String}> with one
37 * element for each occurence of the header name in the request or response.
38 * <p>
39 * For example, if a response header instance contains one key "HeaderName" with two values "value1 and value2"
40 * then this object is output as two header lines:
41 * <blockquote><pre>
42 * HeaderName: value1
43 * HeaderName: value2
44 * </blockquote></pre>
45 * <p>
46 * All the normal {@link java.util.Map} methods are provided, but the following
47 * additional convenience methods are most likely to be used:
48 * <ul>
49 * <li>{@link #getFirst(String)} returns a single valued header or the first value of
50 * a multi-valued header.</li>
51 * <li>{@link #add(String,String)} adds the given header value to the list for the given key</li>
52 * <li>{@link #set(String,String)} sets the given header field to the single value given
53 * overwriting any existing values in the value list.
54 * </ul><p>
55 * All methods in this class accept <code>null</code> values for keys and values. However, null
56 * keys will never will be present in HTTP request headers, and will not be output/sent in response headers.
57 * Null values can be represented as either a null entry for the key (i.e. the list is null) or
58 * where the key has a list, but one (or more) of the list's values is null. Null values are output
59 * as a header line containing the key but no associated value.
60 * @since 1.6
61 */
62 public class Headers implements Map<String,List<String>> {
63
64 HashMap<String,List<String>> map;
65
66 public Headers () {map = new HashMap<String,List<String>>(32);}
67
68 /* Normalize the key by converting to following form.
69 * First char upper case, rest lower case.
70 * key is presumed to be ASCII
71 */
72 private String normalize (String key) {
73 if (key == null) {
74 return null;
75 }
76 int len = key.length();
77 if (len == 0) {
78 return key;
79 }
80 char[] b = new char [len];
81 String s = null;
82 b = key.toCharArray();
83 if (b[0] >= 'a' && b[0] <= 'z') {
84 b[0] = (char)(b[0] - ('a' - 'A'));
85 }
86 for (int i=1; i<len; i++) {
87 if (b[i] >= 'A' && b[i] <= 'Z') {
88 b[i] = (char) (b[i] + ('a' - 'A'));
89 }
90 }
91 s = new String (b);
92 return s;
93 }
94
95 public int size() {return map.size();}
96
97 public boolean isEmpty() {return map.isEmpty();}
98
99 public boolean containsKey(Object key) {
100 if (key == null) {
101 return false;
102 }
103 if (!(key instanceof String)) {
104 return false;
105 }
106 return map.containsKey (normalize((String)key));
107 }
108
109 public boolean containsValue(Object value) {
110 return map.containsValue(value);
111 }
112
113 public List<String> get(Object key) {
114 return map.get(normalize((String)key));
115 }
116
117 /**
118 * returns the first value from the List of String values
119 * for the given key (if at least one exists).
120 * @param key the key to search for
121 * @return the first string value associated with the key
122 */
123 public String getFirst (String key) {
124 List<String> l = map.get(normalize((String)key));
125 if (l == null) {
126 return null;
127 }
128 return l.get(0);
129 }
130
131 public List<String> put(String key, List<String> value) {
132 return map.put (normalize(key), value);
133 }
134
135 /**
136 * adds the given value to the list of headers
137 * for the given key. If the mapping does not
138 * already exist, then it is created
139 * @param key the header name
140 * @param value the header value to add to the header
141 */
142 public void add (String key, String value) {
143 String k = normalize(key);
144 List<String> l = map.get(k);
145 if (l == null) {
146 l = new LinkedList<String>();
147 map.put(k,l);
148 }
149 l.add (value);
150 }
151
152 /**
153 * sets the given value as the sole header value
154 * for the given key. If the mapping does not
155 * already exist, then it is created
156 * @param key the header name
157 * @param value the header value to set.
158 */
159 public void set (String key, String value) {
160 LinkedList<String> l = new LinkedList<String>();
161 l.add (value);
162 put (key, l);
163 }
164
165
166 public List<String> remove(Object key) {
167 return map.remove(normalize((String)key));
168 }
169
170 public void putAll(Map<? extends String,? extends List<String>> t) {
171 map.putAll (t);
172 }
173
174 public void clear() {map.clear();}
175
176 public Set<String> keySet() {return map.keySet();}
177
178 public Collection<List<String>> values() {return map.values();}
179
180 public Set<Map.Entry<String, List<String>>> entrySet() {
181 return map.entrySet();
182 }
183
184 public boolean equals(Object o) {return map.equals(o);}
185
186 public int hashCode() {return map.hashCode();}
187 }