public class IntHashMap extends Object
A hash map that uses primitive ints for the key rather than objects.
Note that this class is for internal optimization purposes only, and may not be supported in future releases of Apache Commons Lang. Utilities of this sort may be included in future releases of Apache Commons Collections.
HashMap| Constructor and Description |
|---|
IntHashMap()
Constructs a new, empty hashtable with a default capacity and load
factor, which is
20 and 0.75 respectively. |
IntHashMap(int initialCapacity)
Constructs a new, empty hashtable with the specified initial capacity
and default load factor, which is
0.75. |
IntHashMap(int initialCapacity,
float loadFactor)
Constructs a new, empty hashtable with the specified initial
capacity and the specified load factor.
|
| Modifier and Type | Method and Description |
|---|---|
void |
clear()
Clears this hashtable so that it contains no keys.
|
boolean |
contains(Object value)
Tests if some key maps into the specified value in this hashtable.
|
boolean |
containsKey(int key)
Tests if the specified object is a key in this hashtable.
|
boolean |
containsValue(Object value)
Returns
true if this HashMap maps one or more keys
to this value. |
Object |
get(int key)
Returns the value to which the specified key is mapped in this map.
|
boolean |
isEmpty()
Tests if this hashtable maps no keys to values.
|
Object |
put(int key,
Object value)
Maps the specified
key to the specified
value in this hashtable. |
protected void |
rehash()
Increases the capacity of and internally reorganizes this
hashtable, in order to accommodate and access its entries more
efficiently.
|
Object |
remove(int key)
Removes the key (and its corresponding value) from this
hashtable.
|
int |
size()
Returns the number of keys in this hashtable.
|
public IntHashMap()
Constructs a new, empty hashtable with a default capacity and load
factor, which is 20 and 0.75 respectively.
public IntHashMap(int initialCapacity)
Constructs a new, empty hashtable with the specified initial capacity
and default load factor, which is 0.75.
initialCapacity - the initial capacity of the hashtable.IllegalArgumentException - if the initial capacity is less
than zero.public IntHashMap(int initialCapacity,
float loadFactor)
Constructs a new, empty hashtable with the specified initial capacity and the specified load factor.
initialCapacity - the initial capacity of the hashtable.loadFactor - the load factor of the hashtable.IllegalArgumentException - if the initial capacity is less
than zero, or if the load factor is nonpositive.public int size()
Returns the number of keys in this hashtable.
public boolean isEmpty()
Tests if this hashtable maps no keys to values.
true if this hashtable maps no keys to values;
false otherwise.public boolean contains(Object value)
Tests if some key maps into the specified value in this hashtable.
This operation is more expensive than the containsKey
method.
Note that this method is identical in functionality to containsValue, (which is part of the Map interface in the collections framework).
value - a value to search for.true if and only if some key maps to the
value argument in this hashtable as
determined by the equals method;
false otherwise.NullPointerException - if the value is null.containsKey(int),
containsValue(Object),
Mappublic boolean containsValue(Object value)
Returns true if this HashMap maps one or more keys
to this value.
Note that this method is identical in functionality to contains (which predates the Map interface).
value - value whose presence in this HashMap is to be tested.true if the value is containedMappublic boolean containsKey(int key)
Tests if the specified object is a key in this hashtable.
key - possible key.true if and only if the specified object is a
key in this hashtable, as determined by the equals
method; false otherwise.contains(Object)public Object get(int key)
Returns the value to which the specified key is mapped in this map.
key - a key in the hashtable.null if the key is not mapped to any value in
this hashtable.put(int, Object)protected void rehash()
Increases the capacity of and internally reorganizes this hashtable, in order to accommodate and access its entries more efficiently.
This method is called automatically when the number of keys in the hashtable exceeds this hashtable's capacity and load factor.
public Object put(int key, Object value)
Maps the specified key to the specified
value in this hashtable. The key cannot be
null.
The value can be retrieved by calling the get method
with a key that is equal to the original key.
key - the hashtable key.value - the value.null if it did not have one.NullPointerException - if the key is null.get(int)public Object remove(int key)
Removes the key (and its corresponding value) from this hashtable.
This method does nothing if the key is not present in the hashtable.
key - the key that needs to be removed.null if the key did not have a mapping.public void clear()
Clears this hashtable so that it contains no keys.
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