|
JAC project AOPSYS CEDRIC & LIP6 labs |
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Object | +--org.objectweb.jac.util.AbstractMap | +--org.objectweb.jac.util.WeakHashMap
A hashtable-based Map implementation with weak walues. An entry in a WeakHashMap will automatically be removed when its value is no longer in ordinary use. More precisely, the presence of a mapping for a given key will not prevent the value from being discarded by the garbage collector, that is, made finalizable, finalized, and then reclaimed. When a value has been discarded its entry is effectively removed from the map, so this class behaves somewhat differently than other Map implementations.
Both null values and the null key are supported. This class has performance characteristics similar to those of the HashMap class, and has the same efficiency parameters of initial capacity and load factor.
Like most collection classes, this class is not synchronized. A synchronized WeakHashMap may be constructed using the Collections.synchronizedMap method.
HashMap
,
WeakReference
Constructor Summary | |
WeakHashMap()
Constructs a new, empty WeakHashMap with the default initial capacity (16) and the default load factor (0.75). |
|
WeakHashMap(int initialCapacity)
Constructs a new, empty WeakHashMap with the given initial capacity and the default load factor, which is 0.75. |
|
WeakHashMap(int initialCapacity,
float loadFactor)
Constructs a new, empty WeakHashMap with the given initial capacity and the given load factor. |
|
WeakHashMap(Map t)
Constructs a new WeakHashMap with the same mappings as the specified Map. |
Method Summary | |
void |
clear()
Removes all mappings from this map. |
boolean |
containsKey(Object key)
Returns true if this map contains a mapping for the specified key. |
boolean |
containsValue(Object value)
Returns true if this map maps one or more keys to the specified value. |
Set |
entrySet()
Returns a collection view of the mappings contained in this map. |
Object |
get(Object key)
Returns the value to which the specified key is mapped in this weak hash map, or null if the map contains no mapping for this key. |
boolean |
isEmpty()
Returns true if this map contains no key-value mappings. |
Object |
put(Object key,
Object value)
Associates the specified value with the specified key in this map. |
void |
putAll(Map t)
Copies all of the mappings from the specified map to this map These mappings will replace any mappings that this map had for any of the keys currently in the specified map. |
Object |
remove(Object key)
Removes the mapping for this key from this map if present. |
int |
size()
Returns the number of key-value mappings in this map. |
Collection |
values()
Returns a collection view of the values contained in this map. |
Methods inherited from class org.objectweb.jac.util.AbstractMap |
clone, equals, hashCode, keySet, toString |
Methods inherited from class java.lang.Object |
finalize, getClass, notify, notifyAll, wait, wait, wait |
Methods inherited from interface java.util.Map |
equals, hashCode, keySet |
Constructor Detail |
public WeakHashMap(int initialCapacity, float loadFactor)
initialCapacity
- The initial capacity of the WeakHashMaploadFactor
- The load factor of the WeakHashMap
IllegalArgumentException
- If the initial capacity is negative,
or if the load factor is nonpositive.public WeakHashMap(int initialCapacity)
initialCapacity
- The initial capacity of the WeakHashMap
IllegalArgumentException
- If the initial capacity is negative.public WeakHashMap()
public WeakHashMap(Map t)
t
- the map whose mappings are to be placed in this map.
NullPointerException
- if the specified map is null.Method Detail |
public int size()
size
in interface Map
size
in class AbstractMap
public boolean isEmpty()
isEmpty
in interface Map
isEmpty
in class AbstractMap
public Object get(Object key)
get
in interface Map
get
in class AbstractMap
key
- the key whose associated value is to be returned.
put(Object, Object)
public boolean containsKey(Object key)
containsKey
in interface Map
containsKey
in class AbstractMap
key
- The key whose presence in this map is to be tested
public Object put(Object key, Object value)
put
in interface Map
put
in class AbstractMap
key
- key with which the specified value is to be associated.value
- value to be associated with the specified key.
public void putAll(Map t)
putAll
in interface Map
putAll
in class AbstractMap
t
- mappings to be stored in this map.
NullPointerException
- if the specified map is null.public Object remove(Object key)
remove
in interface Map
remove
in class AbstractMap
key
- key whose mapping is to be removed from the map.
public void clear()
clear
in interface Map
clear
in class AbstractMap
public boolean containsValue(Object value)
containsValue
in interface Map
containsValue
in class AbstractMap
value
- value whose presence in this map is to be tested.
public Collection values()
values
in interface Map
values
in class AbstractMap
public Set entrySet()
entrySet
in interface Map
entrySet
in class AbstractMap
Map.Entry
|
Contact JAC development team: Renaud Pawlak Lionel Seinturier Laurent Martelli |
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |