public class KeyCollectionAsMap<E,K>
extends java.lang.Object
implements java.util.Map<K,E>, java.io.Serializable
| Constructor and Description |
|---|
KeyCollectionAsMap(KeyCollectionImpl<E> coll,
int keyIndex,
boolean immutable) |
| Modifier and Type | Method and Description |
|---|---|
void |
clear()
Removes all of the mappings from this map (optional operation).
|
boolean |
containsKey(java.lang.Object key)
Returns true if this map contains a mapping for the specified
key.
|
boolean |
containsValue(java.lang.Object value)
Returns true if this map maps one or more keys to the
specified value.
|
java.util.Set<java.util.Map.Entry<K,E>> |
entrySet()
Returns a
Set view of the mappings contained in this map. |
boolean |
equals(java.lang.Object o)
Indicates whether some other object is "equal to" this one.
|
E |
get(java.lang.Object key)
Returns the value to which the specified key is mapped,
or
null if this map contains no mapping for the key. |
int |
hashCode()
Returns a hash code value for the object.
|
boolean |
isEmpty()
Returns true if this map contains no key-value mappings.
|
java.util.Set<K> |
keySet()
Returns a
Set view of the keys contained in this map. |
E |
put(K key,
E elem)
Associates the specified value with the specified key in this map
(optional operation).
|
void |
putAll(java.util.Map<? extends K,? extends E> map)
Copies all of the mappings from the specified map to this map
(optional operation).
|
E |
remove(java.lang.Object key)
Removes the mapping for a key from this map if it is present
(optional operation).
|
int |
size()
Returns the number of key-value mappings in this map.
|
java.lang.String |
toString()
Returns a string representation of the object.
|
java.util.Collection<E> |
values()
Returns a
Collection view of the values contained in this map. |
public KeyCollectionAsMap(KeyCollectionImpl<E> coll, int keyIndex, boolean immutable)
public boolean equals(java.lang.Object o)
java.lang.Object
The equals method implements an equivalence relation
on non-null object references:
x, x.equals(x) should return
true.
x and y, x.equals(y)
should return true if and only if
y.equals(x) returns true.
x, y, and z, if
x.equals(y) returns true and
y.equals(z) returns true, then
x.equals(z) should return true.
x and y, multiple invocations of
x.equals(y) consistently return true
or consistently return false, provided no
information used in equals comparisons on the
objects is modified.
x,
x.equals(null) should return false.
The equals method for class Object implements
the most discriminating possible equivalence relation on objects;
that is, for any non-null reference values x and
y, this method returns true if and only
if x and y refer to the same object
(x == y has the value true).
Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.
public int hashCode()
java.lang.Objectjava.util.Hashtable.
The general contract of hashCode is:
hashCode method on each of
the two objects must produce the same integer result.
Object.equals(java.lang.Object)
method, then calling the hashCode method on each of the
two objects must produce distinct integer results. However, the
programmer should be aware that producing distinct integer results
for unequal objects may improve the performance of hashtables.
As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the JavaTM programming language.)
public java.lang.String toString()
java.lang.ObjecttoString method returns a string that
"textually represents" this object. The result should
be a concise but informative representation that is easy for a
person to read.
It is recommended that all subclasses override this method.
The toString method for class Object
returns a string consisting of the name of the class of which the
object is an instance, the at-sign character `@', and
the unsigned hexadecimal representation of the hash code of the
object. In other words, this method returns a string equal to the
value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
toString in class java.lang.Objectpublic int size()
java.util.Mappublic boolean isEmpty()
java.util.Mappublic boolean containsKey(java.lang.Object key)
java.util.Mappublic boolean containsValue(java.lang.Object value)
java.util.Mappublic E get(java.lang.Object key)
java.util.Mapnull if this map contains no mapping for the key.
More formally, if this map contains a mapping from a key
k to a value v such that (key==null ? k==null :
key.equals(k)), then this method returns v; otherwise
it returns null. (There can be at most one such mapping.)
If this map permits null values, then a return value of
null does not necessarily indicate that the map
contains no mapping for the key; it's also possible that the map
explicitly maps the key to null. The containsKey operation may be used to distinguish these two cases.
public java.util.Set<K> keySet()
Set view of the keys contained in this map.
The set is backed by the map, so changes to the map are
reflected in the set, and vice-versa. If the map is modified
while an iteration over the set is in progress (except through
the iterator's own remove operation), the results of
the iteration are undefined. The set supports element removal,
which removes the corresponding mapping from the map, via the
Iterator.remove, Set.remove,
removeAll, retainAll, and clear
operations. It does not support the add or addAll
operations.
Note that the returned set is immutable.
public java.util.Set<java.util.Map.Entry<K,E>> entrySet()
Set view of the mappings contained in this map.
The set is backed by the map, so changes to the map are
reflected in the set, and vice-versa. If the map is modified
while an iteration over the set is in progress (except through
the iterator's own remove operation, or through the
setValue operation on a map entry returned by the
iterator) the results of the iteration are undefined. The set
supports element removal, which removes the corresponding
mapping from the map, via the Iterator.remove,
Set.remove, removeAll, retainAll and
clear operations. It does not support the
add or addAll operations.
Note that the returned set is immutable.
public java.util.Collection<E> values()
java.util.MapCollection view of the values contained in this map.
The collection is backed by the map, so changes to the map are
reflected in the collection, and vice-versa. If the map is
modified while an iteration over the collection is in progress
(except through the iterator's own remove operation),
the results of the iteration are undefined. The collection
supports element removal, which removes the corresponding
mapping from the map, via the Iterator.remove,
Collection.remove, removeAll,
retainAll and clear operations. It does not
support the add or addAll operations.public void clear()
java.util.Mappublic E put(K key, E elem)
java.util.Mapm.containsKey(k) would return
true.)put in interface java.util.Map<K,E>key - key with which the specified value is to be associatedelem - value to be associated with the specified keypublic E remove(java.lang.Object key)
java.util.Map(key==null ? k==null : key.equals(k)), that mapping
is removed. (The map can contain at most one such mapping.)
Returns the value to which this map previously associated the key, or null if the map contained no mapping for the key.
If this map permits null values, then a return value of null does not necessarily indicate that the map contained no mapping for the key; it's also possible that the map explicitly mapped the key to null.
The map will not contain a mapping for the specified key once the call returns.
public void putAll(java.util.Map<? extends K,? extends E> map)
java.util.Mapput(k, v) on this map once
for each mapping from key k to value v in the
specified map. The behavior of this operation is undefined if the
specified map is modified while the operation is in progress.