1 |
dl |
1.1 |
/* |
2 |
|
|
* Written by Doug Lea with assistance from members of JCP JSR-166 |
3 |
|
|
* Expert Group and released to the public domain, as explained at |
4 |
|
|
* http://creativecommons.org/licenses/publicdomain |
5 |
|
|
*/ |
6 |
|
|
|
7 |
|
|
package jsr166x; |
8 |
|
|
|
9 |
|
|
import java.util.*; |
10 |
|
|
|
11 |
|
|
/** |
12 |
dl |
1.4 |
* A {@link SortedMap} extended with navigation methods returning the |
13 |
|
|
* closest matches for given search targets. Methods |
14 |
|
|
* <tt>lowerEntry</tt>, <tt>floorEntry</tt>, <tt>ceilingEntry</tt>, |
15 |
|
|
* and <tt>higherEntry</tt> return <tt>Map.Entry</tt> objects |
16 |
|
|
* associated with keys respectively less than, less than or equal, |
17 |
|
|
* greater than or equal, and greater than a given key, returning |
18 |
|
|
* <tt>null</tt> if there is no such key. Similarly, methods |
19 |
|
|
* <tt>lowerKey</tt>, <tt>floorKey</tt>, <tt>ceilingKey</tt>, and |
20 |
|
|
* <tt>higherKey</tt> return only the associated keys. All of these |
21 |
|
|
* methods are designed for locating, not traversing entries. |
22 |
dl |
1.3 |
* |
23 |
|
|
* <p>A <tt>NavigableMap</tt> may be viewed and traversed in either |
24 |
|
|
* ascending or descending key order. The <tt>Map</tt> methods |
25 |
dl |
1.4 |
* <tt>keySet</tt> and <tt>entrySet</tt> return ascending views, and |
26 |
dl |
1.3 |
* the additional methods <tt>descendingKeySet</tt> and |
27 |
dl |
1.4 |
* <tt>descendingEntrySet</tt> return descending views. The |
28 |
dl |
1.3 |
* performance of ascending traversals is likely to be faster than |
29 |
|
|
* descending traversals. Notice that it is possible to perform |
30 |
|
|
* subrannge traversals in either direction using <tt>SubMap</tt>. |
31 |
jsr166 |
1.5 |
* |
32 |
dl |
1.3 |
* <p>This interface additionally defines methods <tt>firstEntry</tt>, |
33 |
dl |
1.2 |
* <tt>pollFirstEntry</tt>, <tt>lastEntry</tt>, and |
34 |
|
|
* <tt>pollLastEntry</tt> that return and/or remove the least and |
35 |
|
|
* greatest mappings, if any exist, else returning <tt>null</tt>. |
36 |
dl |
1.1 |
* |
37 |
dl |
1.3 |
* <p> Implementations of entry-returning methods are expected to |
38 |
|
|
* return <tt>Map.Entry</tt> pairs representing snapshots of mappings |
39 |
|
|
* at the time they were produced, and thus generally do <em>not</em> |
40 |
|
|
* support the optional <tt>Entry.setValue</tt> method. Note however |
41 |
|
|
* that it is possible to change mappings in the associated map using |
42 |
|
|
* method <tt>put</tt>. |
43 |
dl |
1.1 |
* |
44 |
|
|
* @author Doug Lea |
45 |
|
|
* @param <K> the type of keys maintained by this map |
46 |
jsr166 |
1.5 |
* @param <V> the type of mapped values |
47 |
dl |
1.1 |
*/ |
48 |
|
|
public interface NavigableMap<K,V> extends SortedMap<K,V> { |
49 |
|
|
/** |
50 |
|
|
* Returns a key-value mapping associated with the least key |
51 |
dl |
1.2 |
* greater than or equal to the given key, or <tt>null</tt> if there is |
52 |
jsr166 |
1.5 |
* no such entry. |
53 |
|
|
* |
54 |
dl |
1.1 |
* @param key the key. |
55 |
dl |
1.2 |
* @return an Entry associated with ceiling of given key, or <tt>null</tt> |
56 |
dl |
1.1 |
* if there is no such Entry. |
57 |
|
|
* @throws ClassCastException if key cannot be compared with the keys |
58 |
|
|
* currently in the map. |
59 |
|
|
* @throws NullPointerException if key is <tt>null</tt> and this map |
60 |
|
|
* does not support <tt>null</tt> keys. |
61 |
|
|
*/ |
62 |
|
|
public Map.Entry<K,V> ceilingEntry(K key); |
63 |
|
|
|
64 |
|
|
/** |
65 |
dl |
1.3 |
* Returns least key greater than or equal to the given key, or |
66 |
|
|
* <tt>null</tt> if there is no such key. |
67 |
jsr166 |
1.5 |
* |
68 |
dl |
1.3 |
* @param key the key. |
69 |
|
|
* @return the ceiling key, or <tt>null</tt> |
70 |
|
|
* if there is no such key. |
71 |
|
|
* @throws ClassCastException if key cannot be compared with the keys |
72 |
|
|
* currently in the map. |
73 |
|
|
* @throws NullPointerException if key is <tt>null</tt> and this map |
74 |
|
|
* does not support <tt>null</tt> keys. |
75 |
|
|
*/ |
76 |
|
|
public K ceilingKey(K key); |
77 |
|
|
|
78 |
|
|
/** |
79 |
dl |
1.1 |
* Returns a key-value mapping associated with the greatest |
80 |
dl |
1.2 |
* key strictly less than the given key, or <tt>null</tt> if there is no |
81 |
jsr166 |
1.5 |
* such entry. |
82 |
|
|
* |
83 |
dl |
1.1 |
* @param key the key. |
84 |
|
|
* @return an Entry with greatest key less than the given |
85 |
dl |
1.2 |
* key, or <tt>null</tt> if there is no such Entry. |
86 |
dl |
1.1 |
* @throws ClassCastException if key cannot be compared with the keys |
87 |
|
|
* currently in the map. |
88 |
|
|
* @throws NullPointerException if key is <tt>null</tt> and this map |
89 |
|
|
* does not support <tt>null</tt> keys. |
90 |
|
|
*/ |
91 |
|
|
public Map.Entry<K,V> lowerEntry(K key); |
92 |
|
|
|
93 |
|
|
/** |
94 |
dl |
1.3 |
* Returns the greatest key strictly less than the given key, or |
95 |
|
|
* <tt>null</tt> if there is no such key. |
96 |
jsr166 |
1.5 |
* |
97 |
dl |
1.3 |
* @param key the key. |
98 |
|
|
* @return the greatest key less than the given |
99 |
|
|
* key, or <tt>null</tt> if there is no such key. |
100 |
|
|
* @throws ClassCastException if key cannot be compared with the keys |
101 |
|
|
* currently in the map. |
102 |
|
|
* @throws NullPointerException if key is <tt>null</tt> and this map |
103 |
|
|
* does not support <tt>null</tt> keys. |
104 |
|
|
*/ |
105 |
|
|
public K lowerKey(K key); |
106 |
|
|
|
107 |
|
|
/** |
108 |
|
|
* Returns a key-value mapping associated with the greatest key |
109 |
|
|
* less than or equal to the given key, or <tt>null</tt> if there |
110 |
|
|
* is no such entry. |
111 |
jsr166 |
1.5 |
* |
112 |
dl |
1.1 |
* @param key the key. |
113 |
dl |
1.2 |
* @return an Entry associated with floor of given key, or <tt>null</tt> |
114 |
dl |
1.1 |
* if there is no such Entry. |
115 |
|
|
* @throws ClassCastException if key cannot be compared with the keys |
116 |
|
|
* currently in the map. |
117 |
|
|
* @throws NullPointerException if key is <tt>null</tt> and this map |
118 |
|
|
* does not support <tt>null</tt> keys. |
119 |
|
|
*/ |
120 |
|
|
public Map.Entry<K,V> floorEntry(K key); |
121 |
|
|
|
122 |
|
|
/** |
123 |
dl |
1.3 |
* Returns the greatest key |
124 |
|
|
* less than or equal to the given key, or <tt>null</tt> if there |
125 |
|
|
* is no such key. |
126 |
jsr166 |
1.5 |
* |
127 |
dl |
1.3 |
* @param key the key. |
128 |
|
|
* @return the floor of given key, or <tt>null</tt> if there is no |
129 |
|
|
* such key. |
130 |
|
|
* @throws ClassCastException if key cannot be compared with the keys |
131 |
|
|
* currently in the map. |
132 |
|
|
* @throws NullPointerException if key is <tt>null</tt> and this map |
133 |
|
|
* does not support <tt>null</tt> keys. |
134 |
|
|
*/ |
135 |
|
|
public K floorKey(K key); |
136 |
|
|
|
137 |
|
|
/** |
138 |
|
|
* Returns a key-value mapping associated with the least key |
139 |
|
|
* strictly greater than the given key, or <tt>null</tt> if there |
140 |
|
|
* is no such entry. |
141 |
jsr166 |
1.5 |
* |
142 |
dl |
1.1 |
* @param key the key. |
143 |
|
|
* @return an Entry with least key greater than the given key, or |
144 |
dl |
1.2 |
* <tt>null</tt> if there is no such Entry. |
145 |
dl |
1.1 |
* @throws ClassCastException if key cannot be compared with the keys |
146 |
|
|
* currently in the map. |
147 |
|
|
* @throws NullPointerException if key is <tt>null</tt> and this map |
148 |
|
|
* does not support <tt>null</tt> keys. |
149 |
|
|
*/ |
150 |
|
|
public Map.Entry<K,V> higherEntry(K key); |
151 |
|
|
|
152 |
|
|
/** |
153 |
dl |
1.3 |
* Returns the least key strictly greater than the given key, or |
154 |
|
|
* <tt>null</tt> if there is no such key. |
155 |
jsr166 |
1.5 |
* |
156 |
dl |
1.3 |
* @param key the key. |
157 |
|
|
* @return the least key greater than the given key, or |
158 |
|
|
* <tt>null</tt> if there is no such key. |
159 |
|
|
* @throws ClassCastException if key cannot be compared with the keys |
160 |
|
|
* currently in the map. |
161 |
|
|
* @throws NullPointerException if key is <tt>null</tt> and this map |
162 |
|
|
* does not support <tt>null</tt> keys. |
163 |
|
|
*/ |
164 |
|
|
public K higherKey(K key); |
165 |
|
|
|
166 |
|
|
/** |
167 |
dl |
1.1 |
* Returns a key-value mapping associated with the least |
168 |
dl |
1.2 |
* key in this map, or <tt>null</tt> if the map is empty. |
169 |
jsr166 |
1.5 |
* |
170 |
|
|
* @return an Entry with least key, or <tt>null</tt> |
171 |
dl |
1.1 |
* if the map is empty. |
172 |
|
|
*/ |
173 |
|
|
public Map.Entry<K,V> firstEntry(); |
174 |
|
|
|
175 |
|
|
/** |
176 |
|
|
* Returns a key-value mapping associated with the greatest |
177 |
dl |
1.2 |
* key in this map, or <tt>null</tt> if the map is empty. |
178 |
jsr166 |
1.5 |
* |
179 |
dl |
1.2 |
* @return an Entry with greatest key, or <tt>null</tt> |
180 |
dl |
1.1 |
* if the map is empty. |
181 |
|
|
*/ |
182 |
|
|
public Map.Entry<K,V> lastEntry(); |
183 |
|
|
|
184 |
|
|
/** |
185 |
|
|
* Removes and returns a key-value mapping associated with |
186 |
dl |
1.2 |
* the least key in this map, or <tt>null</tt> if the map is empty. |
187 |
jsr166 |
1.5 |
* |
188 |
dl |
1.2 |
* @return the removed first entry of this map, or <tt>null</tt> |
189 |
dl |
1.1 |
* if the map is empty. |
190 |
|
|
*/ |
191 |
|
|
public Map.Entry<K,V> pollFirstEntry(); |
192 |
|
|
|
193 |
|
|
/** |
194 |
|
|
* Removes and returns a key-value mapping associated with |
195 |
dl |
1.2 |
* the greatest key in this map, or <tt>null</tt> if the map is empty. |
196 |
jsr166 |
1.5 |
* |
197 |
dl |
1.2 |
* @return the removed last entry of this map, or <tt>null</tt> |
198 |
dl |
1.1 |
* if the map is empty. |
199 |
|
|
*/ |
200 |
|
|
public Map.Entry<K,V> pollLastEntry(); |
201 |
|
|
|
202 |
|
|
/** |
203 |
dl |
1.3 |
* Returns a set view of the keys contained in this map, in |
204 |
|
|
* descending key order. The set is backed by the map, so changes |
205 |
|
|
* to the map are reflected in the set, and vice-versa. If the |
206 |
|
|
* map is modified while an iteration over the set is in progress |
207 |
|
|
* (except through the iterator's own <tt>remove</tt> operation), |
208 |
|
|
* the results of the iteration are undefined. The set supports |
209 |
|
|
* element removal, which removes the corresponding mapping from |
210 |
|
|
* the map, via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>, |
211 |
|
|
* <tt>removeAll</tt> <tt>retainAll</tt>, and <tt>clear</tt> |
212 |
|
|
* operations. It does not support the add or <tt>addAll</tt> |
213 |
|
|
* operations. |
214 |
|
|
* |
215 |
|
|
* @return a set view of the keys contained in this map. |
216 |
|
|
*/ |
217 |
|
|
Set<K> descendingKeySet(); |
218 |
|
|
|
219 |
|
|
/** |
220 |
|
|
* Returns a set view of the mappings contained in this map, in |
221 |
|
|
* descending key order. Each element in the returned set is a |
222 |
dl |
1.4 |
* <tt>Map.Entry</tt>. The set is backed by the map, so changes to |
223 |
dl |
1.3 |
* the map are reflected in the set, and vice-versa. If the map |
224 |
|
|
* is modified while an iteration over the set is in progress |
225 |
|
|
* (except through the iterator's own <tt>remove</tt> operation, |
226 |
|
|
* or through the <tt>setValue</tt> operation on a map entry |
227 |
|
|
* returned by the iterator) the results of the iteration are |
228 |
|
|
* undefined. The set supports element removal, which removes the |
229 |
|
|
* corresponding mapping from the map, via the |
230 |
|
|
* <tt>Iterator.remove</tt>, <tt>Set.remove</tt>, |
231 |
|
|
* <tt>removeAll</tt>, <tt>retainAll</tt> and <tt>clear</tt> |
232 |
|
|
* operations. It does not support the <tt>add</tt> or |
233 |
|
|
* <tt>addAll</tt> operations. |
234 |
|
|
* |
235 |
|
|
* @return a set view of the mappings contained in this map. |
236 |
|
|
*/ |
237 |
|
|
Set<Map.Entry<K, V>> descendingEntrySet(); |
238 |
|
|
|
239 |
|
|
/** |
240 |
dl |
1.1 |
* Returns a view of the portion of this map whose keys range from |
241 |
|
|
* <tt>fromKey</tt>, inclusive, to <tt>toKey</tt>, exclusive. (If |
242 |
|
|
* <tt>fromKey</tt> and <tt>toKey</tt> are equal, the returned sorted map |
243 |
|
|
* is empty.) The returned sorted map is backed by this map, so changes |
244 |
|
|
* in the returned sorted map are reflected in this map, and vice-versa. |
245 |
|
|
|
246 |
|
|
* @param fromKey low endpoint (inclusive) of the subMap. |
247 |
|
|
* @param toKey high endpoint (exclusive) of the subMap. |
248 |
|
|
* |
249 |
|
|
* @return a view of the portion of this map whose keys range from |
250 |
|
|
* <tt>fromKey</tt>, inclusive, to <tt>toKey</tt>, exclusive. |
251 |
|
|
* |
252 |
|
|
* @throws ClassCastException if <tt>fromKey</tt> and |
253 |
|
|
* <tt>toKey</tt> cannot be compared to one another using this |
254 |
|
|
* map's comparator (or, if the map has no comparator, using |
255 |
|
|
* natural ordering). |
256 |
|
|
* @throws IllegalArgumentException if <tt>fromKey</tt> is greater |
257 |
|
|
* than <tt>toKey</tt>. |
258 |
|
|
* @throws NullPointerException if <tt>fromKey</tt> or |
259 |
|
|
* <tt>toKey</tt> is <tt>null</tt> and this map does not support |
260 |
|
|
* <tt>null</tt> keys. |
261 |
|
|
*/ |
262 |
|
|
public NavigableMap<K,V> subMap(K fromKey, K toKey); |
263 |
|
|
|
264 |
|
|
/** |
265 |
|
|
* Returns a view of the portion of this map whose keys are strictly less |
266 |
|
|
* than <tt>toKey</tt>. The returned sorted map is backed by this map, so |
267 |
|
|
* changes in the returned sorted map are reflected in this map, and |
268 |
jsr166 |
1.5 |
* vice-versa. |
269 |
dl |
1.1 |
* @param toKey high endpoint (exclusive) of the headMap. |
270 |
|
|
* @return a view of the portion of this map whose keys are strictly |
271 |
|
|
* less than <tt>toKey</tt>. |
272 |
|
|
* |
273 |
|
|
* @throws ClassCastException if <tt>toKey</tt> is not compatible |
274 |
|
|
* with this map's comparator (or, if the map has no comparator, |
275 |
|
|
* if <tt>toKey</tt> does not implement <tt>Comparable</tt>). |
276 |
|
|
* @throws NullPointerException if <tt>toKey</tt> is <tt>null</tt> |
277 |
|
|
* and this map does not support <tt>null</tt> keys. |
278 |
|
|
*/ |
279 |
|
|
public NavigableMap<K,V> headMap(K toKey); |
280 |
|
|
|
281 |
|
|
/** |
282 |
|
|
* Returns a view of the portion of this map whose keys are |
283 |
|
|
* greater than or equal to <tt>fromKey</tt>. The returned sorted |
284 |
|
|
* map is backed by this map, so changes in the returned sorted |
285 |
|
|
* map are reflected in this map, and vice-versa. |
286 |
|
|
* @param fromKey low endpoint (inclusive) of the tailMap. |
287 |
|
|
* @return a view of the portion of this map whose keys are greater |
288 |
|
|
* than or equal to <tt>fromKey</tt>. |
289 |
|
|
* @throws ClassCastException if <tt>fromKey</tt> is not compatible |
290 |
|
|
* with this map's comparator (or, if the map has no comparator, |
291 |
|
|
* if <tt>fromKey</tt> does not implement <tt>Comparable</tt>). |
292 |
|
|
* @throws NullPointerException if <tt>fromKey</tt> is <tt>null</tt> |
293 |
|
|
* and this map does not support <tt>null</tt> keys. |
294 |
|
|
*/ |
295 |
|
|
public NavigableMap<K,V> tailMap(K fromKey); |
296 |
|
|
} |