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
26package com.sun.net.httpserver;
27
28import 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 */
64public 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            }
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            return new String(b);
92        }
93
94        public int size() {return map.size();}
95
96        public boolean isEmpty() {return map.isEmpty();}
97
98        public boolean containsKey(Object key) {
99            if (key == null) {
100                return false;
101            }
102            if (!(key instanceof String)) {
103                return false;
104            }
105            return map.containsKey (normalize((String)key));
106        }
107
108        public boolean containsValue(Object value) {
109            return map.containsValue(value);
110        }
111
112        public List<String> get(Object key) {
113            return map.get(normalize((String)key));
114        }
115
116        /**
117         * returns the first value from the List of String values
118         * for the given key (if at least one exists).
119         * @param key the key to search for
120         * @return the first string value associated with the key
121         */
122        public String getFirst (String key) {
123            List<String> l = map.get(normalize(key));
124            if (l == null) {
125                return null;
126            }
127            return l.get(0);
128        }
129
130        public List<String> put(String key, List<String> value) {
131            return map.put (normalize(key), value);
132        }
133
134        /**
135         * adds the given value to the list of headers
136         * for the given key. If the mapping does not
137         * already exist, then it is created
138         * @param key the header name
139         * @param value the header value to add to the header
140         */
141        public void add (String key, String value) {
142            String k = normalize(key);
143            List<String> l = map.get(k);
144            if (l == null) {
145                l = new LinkedList<String>();
146                map.put(k,l);
147            }
148            l.add (value);
149        }
150
151        /**
152         * sets the given value as the sole header value
153         * for the given key. If the mapping does not
154         * already exist, then it is created
155         * @param key the header name
156         * @param value the header value to set.
157         */
158        public void set (String key, String value) {
159            LinkedList<String> l = new LinkedList<String>();
160            l.add (value);
161            put (key, l);
162        }
163
164
165        public List<String> remove(Object key) {
166            return map.remove(normalize((String)key));
167        }
168
169        public void putAll(Map<? extends String,? extends List<String>> t)  {
170            map.putAll (t);
171        }
172
173        public void clear() {map.clear();}
174
175        public Set<String> keySet() {return map.keySet();}
176
177        public Collection<List<String>> values() {return map.values();}
178
179        public Set<Map.Entry<String, List<String>>> entrySet() {
180            return map.entrySet();
181        }
182
183        public boolean equals(Object o) {return map.equals(o);}
184
185        public int hashCode() {return map.hashCode();}
186    }
187