30  * each key can map to at most one value.
37  * or set of key-value mappings.  The <i>order</i> of a map is defined as
46  * object is a key in the map.  A special case of this prohibition is that it
47  * is not permissible for a map to contain itself as a key.  While it is
55  * which creates a new map with the same key-value mappings as its argument.
73  * to insert an ineligible key or value throws an unchecked exception,
75  * Attempting to query the presence of an ineligible key or value may throw an
78  * attempting an operation on an ineligible key or value whose completion
91  * containsKey(Object key)} method says: "returns <tt>true</tt> if and
92  * only if this map contains a mapping for a key <tt>k</tt> such that
93  * <tt>(key==null ? k==null : key.equals(k))</tt>." This specification should
95  * with a non-null argument <tt>key</tt> will cause <tt>key.equals(k)</tt> to
96  * be invoked for any key <tt>k</tt>.  Implementations are free to
121      * Returns the number of key-value mappings in this map.  If the
125      * @return the number of key-value mappings in this map
130      * Returns <tt>true</tt> if this map contains no key-value mappings.
132      * @return <tt>true</tt> if this map contains no key-value mappings
138      * key.  More formally, returns <tt>true</tt> if and only if
139      * this map contains a mapping for a key <tt>k</tt> such that
140      * <tt>(key==null ? k==null : key.equals(k))</tt>.  (There can be
143      * @param key key whose presence in this map is to be tested
145      *         key
146      * @throws ClassCastException if the key is of an inappropriate type for
149      * @throws NullPointerException if the specified key is null and this map
153     boolean containsKey(Object key);
176      * Returns the value to which the specified key is mapped,
177      * or {@code null} if this map contains no mapping for the key.
179      * <p>More formally, if this map contains a mapping from a key
180      * {@code k} to a value {@code v} such that {@code (key==null ? k==null :
181      * key.equals(k))}, then this method returns {@code v}; otherwise
186      * contains no mapping for the key; it's also possible that the map
187      * explicitly maps the key to {@code null}.  The {@link #containsKey
190      * @param key the key whose associated value is to be returned
191      * @return the value to which the specified key is mapped, or
192      *         {@code null} if this map contains no mapping for the key
193      * @throws ClassCastException if the key is of an inappropriate type for
196      * @throws NullPointerException if the specified key is null and this map
200     V get(Object key);
205      * Associates the specified value with the specified key in this map
207      * the key, the old value is replaced by the specified value.  (A map
208      * <tt>m</tt> is said to contain a mapping for a key <tt>k</tt> if and only
212      * @param key key with which the specified value is to be associated
213      * @param value value to be associated with the specified key
214      * @return the previous value associated with <tt>key</tt>, or
215      *         <tt>null</tt> if there was no mapping for <tt>key</tt>.
217      *         previously associated <tt>null</tt> with <tt>key</tt>,
221      * @throws ClassCastException if the class of the specified key or value
223      * @throws NullPointerException if the specified key or value is null
225      * @throws IllegalArgumentException if some property of the specified key
228     V put(K key, V value);
231      * Removes the mapping for a key from this map if it is present
233      * from key <tt>k</tt> to value <tt>v</tt> such that
234      * <code>(key==null ?  k==null : key.equals(k))</code>, that mapping
237      * <p>Returns the value to which this map previously associated the key,
238      * or <tt>null</tt> if the map contained no mapping for the key.
242      * contained no mapping for the key; it's also possible that the map
243      * explicitly mapped the key to <tt>null</tt>.
245      * <p>The map will not contain a mapping for the specified key once the
248      * @param key key whose mapping is to be removed from the map
249      * @return the previous value associated with <tt>key</tt>, or
250      *         <tt>null</tt> if there was no mapping for <tt>key</tt>.
253      * @throws ClassCastException if the key is of an inappropriate type for
256      * @throws NullPointerException if the specified key is null and this
260     V remove(Object key);
269      * for each mapping from key <tt>k</tt> to value <tt>v</tt> in the
276      * @throws ClassCastException if the class of a key or value in the
281      * @throws IllegalArgumentException if some property of a key or value in
351      * A map entry (key-value pair).  The <tt>Map.entrySet</tt> method returns
365          * Returns the key corresponding to this entry.
367          * @return the key corresponding to this entry

Indexes created Tue Jul 24 14:28:13 CEST 2018