15 |
|
* <tt>ceilingEntry</tt>, and <tt>higherEntry</tt> return |
16 |
|
* <tt>Map.Entry</tt> objects associated with keys respectively less |
17 |
|
* than, less than or equal, greater than or equal, and greater than a |
18 |
< |
* given key, returning <tt>null</tt> if there is no such key. These |
19 |
< |
* methods are designed for locating, not traversing entries. To |
20 |
< |
* traverse, use view iterators and/or <tt>submap</tt>. This interface |
21 |
< |
* additionally defines methods <tt>firstEntry</tt>, |
18 |
> |
* given key, returning <tt>null</tt> if there is no such key. |
19 |
> |
* Similarly, methods <tt>lowerKey</tt>, <tt>floorKey</tt>, |
20 |
> |
* <tt>ceilingKey</tt>, and <tt>higherKey</tt> return only the |
21 |
> |
* associated keys. All of these methods are designed for locating, |
22 |
> |
* not traversing entries. |
23 |
> |
* |
24 |
> |
* <p>A <tt>NavigableMap</tt> may be viewed and traversed in either |
25 |
> |
* ascending or descending key order. The <tt>Map</tt> methods |
26 |
> |
* <tt>keySet</tt> and <tt>entrySet</tt>) return ascending views, and |
27 |
> |
* the additional methods <tt>descendingKeySet</tt> and |
28 |
> |
* <tt>descendingEntrySet</tt>) return descending views. The |
29 |
> |
* performance of ascending traversals is likely to be faster than |
30 |
> |
* descending traversals. Notice that it is possible to perform |
31 |
> |
* subrannge traversals in either direction using <tt>SubMap</tt>. |
32 |
> |
* |
33 |
> |
* <p>This interface additionally defines methods <tt>firstEntry</tt>, |
34 |
|
* <tt>pollFirstEntry</tt>, <tt>lastEntry</tt>, and |
35 |
|
* <tt>pollLastEntry</tt> that return and/or remove the least and |
36 |
|
* greatest mappings, if any exist, else returning <tt>null</tt>. |
37 |
|
* |
38 |
< |
* <p> Implementations of these methods are expected to return |
39 |
< |
* <tt>Map.Entry</tt> pairs representing snapshots of mappings at the |
40 |
< |
* time they were produced, and thus generally do <em>not</em> support |
41 |
< |
* the optional <tt>Entry.setValue</tt> method. Note however that it |
42 |
< |
* is possible to change mappings in the associated map using method |
43 |
< |
* <tt>put</tt>. |
38 |
> |
* <p> Implementations of entry-returning methods are expected to |
39 |
> |
* return <tt>Map.Entry</tt> pairs representing snapshots of mappings |
40 |
> |
* at the time they were produced, and thus generally do <em>not</em> |
41 |
> |
* support the optional <tt>Entry.setValue</tt> method. Note however |
42 |
> |
* that it is possible to change mappings in the associated map using |
43 |
> |
* method <tt>put</tt>. |
44 |
|
* |
45 |
|
* @author Doug Lea |
46 |
|
* @param <K> the type of keys maintained by this map |
63 |
|
public Map.Entry<K,V> ceilingEntry(K key); |
64 |
|
|
65 |
|
/** |
66 |
+ |
* Returns least key greater than or equal to the given key, or |
67 |
+ |
* <tt>null</tt> if there is no such key. |
68 |
+ |
* |
69 |
+ |
* @param key the key. |
70 |
+ |
* @return the ceiling key, or <tt>null</tt> |
71 |
+ |
* if there is no such key. |
72 |
+ |
* @throws ClassCastException if key cannot be compared with the keys |
73 |
+ |
* currently in the map. |
74 |
+ |
* @throws NullPointerException if key is <tt>null</tt> and this map |
75 |
+ |
* does not support <tt>null</tt> keys. |
76 |
+ |
*/ |
77 |
+ |
public K ceilingKey(K key); |
78 |
+ |
|
79 |
+ |
/** |
80 |
|
* Returns a key-value mapping associated with the greatest |
81 |
|
* key strictly less than the given key, or <tt>null</tt> if there is no |
82 |
|
* such entry. |
92 |
|
public Map.Entry<K,V> lowerEntry(K key); |
93 |
|
|
94 |
|
/** |
95 |
< |
* Returns a key-value mapping associated with the greatest |
96 |
< |
* key less than or equal to the given key, or <tt>null</tt> if there is no |
97 |
< |
* such entry. |
95 |
> |
* Returns the greatest key strictly less than the given key, or |
96 |
> |
* <tt>null</tt> if there is no such key. |
97 |
> |
* |
98 |
> |
* @param key the key. |
99 |
> |
* @return the greatest key less than the given |
100 |
> |
* key, or <tt>null</tt> if there is no such key. |
101 |
> |
* @throws ClassCastException if key cannot be compared with the keys |
102 |
> |
* currently in the map. |
103 |
> |
* @throws NullPointerException if key is <tt>null</tt> and this map |
104 |
> |
* does not support <tt>null</tt> keys. |
105 |
> |
*/ |
106 |
> |
public K lowerKey(K key); |
107 |
> |
|
108 |
> |
/** |
109 |
> |
* Returns a key-value mapping associated with the greatest key |
110 |
> |
* less than or equal to the given key, or <tt>null</tt> if there |
111 |
> |
* is no such entry. |
112 |
|
* |
113 |
|
* @param key the key. |
114 |
|
* @return an Entry associated with floor of given key, or <tt>null</tt> |
121 |
|
public Map.Entry<K,V> floorEntry(K key); |
122 |
|
|
123 |
|
/** |
124 |
< |
* Returns a key-value mapping associated with the least |
125 |
< |
* key strictly greater than the given key, or <tt>null</tt> if there is no |
126 |
< |
* such entry. |
124 |
> |
* Returns the greatest key |
125 |
> |
* less than or equal to the given key, or <tt>null</tt> if there |
126 |
> |
* is no such key. |
127 |
> |
* |
128 |
> |
* @param key the key. |
129 |
> |
* @return the floor of given key, or <tt>null</tt> if there is no |
130 |
> |
* such key. |
131 |
> |
* @throws ClassCastException if key cannot be compared with the keys |
132 |
> |
* currently in the map. |
133 |
> |
* @throws NullPointerException if key is <tt>null</tt> and this map |
134 |
> |
* does not support <tt>null</tt> keys. |
135 |
> |
*/ |
136 |
> |
public K floorKey(K key); |
137 |
> |
|
138 |
> |
/** |
139 |
> |
* Returns a key-value mapping associated with the least key |
140 |
> |
* strictly greater than the given key, or <tt>null</tt> if there |
141 |
> |
* is no such entry. |
142 |
|
* |
143 |
|
* @param key the key. |
144 |
|
* @return an Entry with least key greater than the given key, or |
151 |
|
public Map.Entry<K,V> higherEntry(K key); |
152 |
|
|
153 |
|
/** |
154 |
+ |
* Returns the least key strictly greater than the given key, or |
155 |
+ |
* <tt>null</tt> if there is no such key. |
156 |
+ |
* |
157 |
+ |
* @param key the key. |
158 |
+ |
* @return the least key greater than the given key, or |
159 |
+ |
* <tt>null</tt> if there is no such key. |
160 |
+ |
* @throws ClassCastException if key cannot be compared with the keys |
161 |
+ |
* currently in the map. |
162 |
+ |
* @throws NullPointerException if key is <tt>null</tt> and this map |
163 |
+ |
* does not support <tt>null</tt> keys. |
164 |
+ |
*/ |
165 |
+ |
public K higherKey(K key); |
166 |
+ |
|
167 |
+ |
/** |
168 |
|
* Returns a key-value mapping associated with the least |
169 |
|
* key in this map, or <tt>null</tt> if the map is empty. |
170 |
|
* |
201 |
|
public Map.Entry<K,V> pollLastEntry(); |
202 |
|
|
203 |
|
/** |
204 |
+ |
* Returns a set view of the keys contained in this map, in |
205 |
+ |
* descending key order. The set is backed by the map, so changes |
206 |
+ |
* to the map are reflected in the set, and vice-versa. If the |
207 |
+ |
* map is modified while an iteration over the set is in progress |
208 |
+ |
* (except through the iterator's own <tt>remove</tt> operation), |
209 |
+ |
* the results of the iteration are undefined. The set supports |
210 |
+ |
* element removal, which removes the corresponding mapping from |
211 |
+ |
* the map, via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>, |
212 |
+ |
* <tt>removeAll</tt> <tt>retainAll</tt>, and <tt>clear</tt> |
213 |
+ |
* operations. It does not support the add or <tt>addAll</tt> |
214 |
+ |
* operations. |
215 |
+ |
* |
216 |
+ |
* @return a set view of the keys contained in this map. |
217 |
+ |
*/ |
218 |
+ |
Set<K> descendingKeySet(); |
219 |
+ |
|
220 |
+ |
/** |
221 |
+ |
* Returns a set view of the mappings contained in this map, in |
222 |
+ |
* descending key order. Each element in the returned set is a |
223 |
+ |
* {@link Map.Entry}. The set is backed by the map, so changes to |
224 |
+ |
* the map are reflected in the set, and vice-versa. If the map |
225 |
+ |
* is modified while an iteration over the set is in progress |
226 |
+ |
* (except through the iterator's own <tt>remove</tt> operation, |
227 |
+ |
* or through the <tt>setValue</tt> operation on a map entry |
228 |
+ |
* returned by the iterator) the results of the iteration are |
229 |
+ |
* undefined. The set supports element removal, which removes the |
230 |
+ |
* corresponding mapping from the map, via the |
231 |
+ |
* <tt>Iterator.remove</tt>, <tt>Set.remove</tt>, |
232 |
+ |
* <tt>removeAll</tt>, <tt>retainAll</tt> and <tt>clear</tt> |
233 |
+ |
* operations. It does not support the <tt>add</tt> or |
234 |
+ |
* <tt>addAll</tt> operations. |
235 |
+ |
* |
236 |
+ |
* @return a set view of the mappings contained in this map. |
237 |
+ |
*/ |
238 |
+ |
Set<Map.Entry<K, V>> descendingEntrySet(); |
239 |
+ |
|
240 |
+ |
/** |
241 |
|
* Returns a view of the portion of this map whose keys range from |
242 |
|
* <tt>fromKey</tt>, inclusive, to <tt>toKey</tt>, exclusive. (If |
243 |
|
* <tt>fromKey</tt> and <tt>toKey</tt> are equal, the returned sorted map |