/
LinkedCaseInsensitiveMap.java
273 lines (235 loc) · 7.24 KB
/
LinkedCaseInsensitiveMap.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
/*
* Copyright 2002-2020 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.util;
import java.io.Serializable;
import java.util.Collection;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import org.springframework.lang.Nullable;
/**
* {@link LinkedHashMap} variant that stores String keys in a case-insensitive
* manner, for example for key-based access in a results table.
*
* <p>Preserves the original order as well as the original casing of keys,
* while allowing for contains, get and remove calls with any case of key.
*
* <p>Does <i>not</i> support {@code null} keys.
*
* @author Juergen Hoeller
* @since 3.0
* @param <V> the value type
*/
@SuppressWarnings("serial")
public class LinkedCaseInsensitiveMap<V> implements Map<String, V>, Serializable, Cloneable {
private final LinkedHashMap<String, V> targetMap;
private final HashMap<String, String> caseInsensitiveKeys;
private final Locale locale;
/**
* Create a new LinkedCaseInsensitiveMap that stores case-insensitive keys
* according to the default Locale (by default in lower case).
* @see #convertKey(String)
*/
public LinkedCaseInsensitiveMap() {
this((Locale) null);
}
/**
* Create a new LinkedCaseInsensitiveMap that stores case-insensitive keys
* according to the given Locale (by default in lower case).
* @param locale the Locale to use for case-insensitive key conversion
* @see #convertKey(String)
*/
public LinkedCaseInsensitiveMap(@Nullable Locale locale) {
this(16, locale);
}
/**
* Create a new LinkedCaseInsensitiveMap that wraps a {@link LinkedHashMap}
* with the given initial capacity and stores case-insensitive keys
* according to the default Locale (by default in lower case).
* @param initialCapacity the initial capacity
* @see #convertKey(String)
*/
public LinkedCaseInsensitiveMap(int initialCapacity) {
this(initialCapacity, null);
}
/**
* Create a new LinkedCaseInsensitiveMap that wraps a {@link LinkedHashMap}
* with the given initial capacity and stores case-insensitive keys
* according to the given Locale (by default in lower case).
* @param initialCapacity the initial capacity
* @param locale the Locale to use for case-insensitive key conversion
* @see #convertKey(String)
*/
public LinkedCaseInsensitiveMap(int initialCapacity, @Nullable Locale locale) {
this.targetMap = new LinkedHashMap<String, V>(initialCapacity) {
@Override
public boolean containsKey(Object key) {
return LinkedCaseInsensitiveMap.this.containsKey(key);
}
@Override
protected boolean removeEldestEntry(Map.Entry<String, V> eldest) {
boolean doRemove = LinkedCaseInsensitiveMap.this.removeEldestEntry(eldest);
if (doRemove) {
caseInsensitiveKeys.remove(convertKey(eldest.getKey()));
}
return doRemove;
}
};
this.caseInsensitiveKeys = new HashMap<>(initialCapacity);
this.locale = (locale != null ? locale : Locale.getDefault());
}
/**
* Copy constructor.
*/
@SuppressWarnings("unchecked")
private LinkedCaseInsensitiveMap(LinkedCaseInsensitiveMap<V> other) {
this.targetMap = (LinkedHashMap<String, V>) other.targetMap.clone();
this.caseInsensitiveKeys = (HashMap<String, String>) other.caseInsensitiveKeys.clone();
this.locale = other.locale;
}
// Implementation of java.util.Map
@Override
public int size() {
return this.targetMap.size();
}
@Override
public boolean isEmpty() {
return this.targetMap.isEmpty();
}
@Override
public boolean containsKey(Object key) {
return (key instanceof String && this.caseInsensitiveKeys.containsKey(convertKey((String) key)));
}
@Override
public boolean containsValue(Object value) {
return this.targetMap.containsValue(value);
}
@Override
@Nullable
public V get(Object key) {
if (key instanceof String) {
String caseInsensitiveKey = this.caseInsensitiveKeys.get(convertKey((String) key));
if (caseInsensitiveKey != null) {
return this.targetMap.get(caseInsensitiveKey);
}
}
return null;
}
@Override
@Nullable
public V getOrDefault(Object key, V defaultValue) {
if (key instanceof String) {
String caseInsensitiveKey = this.caseInsensitiveKeys.get(convertKey((String) key));
if (caseInsensitiveKey != null) {
return this.targetMap.get(caseInsensitiveKey);
}
}
return defaultValue;
}
@Override
@Nullable
public V put(String key, @Nullable V value) {
String oldKey = this.caseInsensitiveKeys.put(convertKey(key), key);
if (oldKey != null && !oldKey.equals(key)) {
this.targetMap.remove(oldKey);
}
return this.targetMap.put(key, value);
}
@Override
public void putAll(Map<? extends String, ? extends V> map) {
if (map.isEmpty()) {
return;
}
map.forEach(this::put);
}
@Override
@Nullable
public V remove(Object key) {
if (key instanceof String) {
String caseInsensitiveKey = this.caseInsensitiveKeys.remove(convertKey((String) key));
if (caseInsensitiveKey != null) {
return this.targetMap.remove(caseInsensitiveKey);
}
}
return null;
}
@Override
public void clear() {
this.caseInsensitiveKeys.clear();
this.targetMap.clear();
}
@Override
public Set<String> keySet() {
return this.targetMap.keySet();
}
@Override
public Collection<V> values() {
return this.targetMap.values();
}
@Override
public Set<Entry<String, V>> entrySet() {
return this.targetMap.entrySet();
}
@Override
public LinkedCaseInsensitiveMap<V> clone() {
return new LinkedCaseInsensitiveMap<>(this);
}
@Override
public boolean equals(@Nullable Object other) {
return (this == other || this.targetMap.equals(other));
}
@Override
public int hashCode() {
return this.targetMap.hashCode();
}
@Override
public String toString() {
return this.targetMap.toString();
}
// Specific to LinkedCaseInsensitiveMap
/**
* Return the locale used by this {@code LinkedCaseInsensitiveMap}.
* Used for case-insensitive key conversion.
* @since 4.3.10
* @see #LinkedCaseInsensitiveMap(Locale)
* @see #convertKey(String)
*/
public Locale getLocale() {
return this.locale;
}
/**
* Convert the given key to a case-insensitive key.
* <p>The default implementation converts the key
* to lower-case according to this Map's Locale.
* @param key the user-specified key
* @return the key to use for storing
* @see String#toLowerCase(Locale)
*/
protected String convertKey(String key) {
return key.toLowerCase(getLocale());
}
/**
* Determine whether this map should remove the given eldest entry.
* @param eldest the candidate entry
* @return {@code true} for removing it, {@code false} for keeping it
* @see LinkedHashMap#removeEldestEntry
*/
protected boolean removeEldestEntry(Map.Entry<String, V> eldest) {
return false;
}
}