WeakSet (Base Utilities API)

java.lang.Object
- java.util.AbstractCollection<E>
- - java.util.AbstractSet<E>
  - - org.openide.util.WeakSet<E>

Type Parameters:

E - the type of elements maintained by this set

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable
```
public class WeakSet<E>
extends java.util.AbstractSet<E>
implements java.lang.Cloneable, java.io.Serializable
```
This class provides storage functionality with Weak-referenced entries and new method putIfAbsent. Set implementation is backed by a hash table. It also provides method resize for changing capacity of internal hash table (can be used for reducing memory occupied by empty set which previously had big number of objects, but they were GCed) Access to set is not thread safe.

See Also:

putIfAbsent(Object), resize(int), Serialized Form

Constructor Summary

Constructors
Constructor	Description
`WeakSet()`	Constructs a new, empty `WeakSet` with the default initial capacity (16) and load factor (0.75).
`WeakSet(int initialCapacity)`	Constructs a new, empty `WeakSet` with the given initial capacity and the default load factor (0.75).
`WeakSet(int initialCapacity, float loadFactor)`	Constructs a new, empty `WeakSet` with the given initial capacity and the given load factor.
`WeakSet(java.util.Collection<? extends E> s)`	Constructs a new `WeakSet` with the same mappings as the specified map.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`add(E e)`
`void`	`clear()`
`java.lang.Object`	`clone()`
`boolean`	`contains(java.lang.Object o)`
`boolean`	`containsAll(java.util.Collection<?> c)`
`boolean`	`equals(java.lang.Object o)`
`int`	`hashCode()`
`boolean`	`isEmpty()`
`java.util.Iterator<E>`	`iterator()`
`E`	`putIfAbsent(E e)`	Put object in this set if equal one is not yet in set.
`boolean`	`remove(java.lang.Object o)`
`boolean`	`removeAll(java.util.Collection<?> c)`
`void`	`resize(int newCapacity)`	compact set if it is empty by setting new capacity
`boolean`	`retainAll(java.util.Collection<?> c)`
`int`	`size()`
`java.lang.Object[]`	`toArray()`
`<T> T[]`	`toArray(T[] a)`
`java.lang.String`	`toString()`

Methods inherited from class java.util.AbstractCollection
addAll

Methods inherited from interface java.util.Collection
parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable
forEach

Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Set
addAll, of, of, of, of, of, of, of, of, of, of, of, of, spliterator

- Constructor Detail
  - WeakSet
```
public WeakSet(int initialCapacity,
               float loadFactor)
```
    Constructs a new, empty WeakSet with the given initial capacity and the given load factor.
    
    Parameters:
    
    initialCapacity - The initial capacity of the WeakSet
    
    loadFactor - The load factor of the WeakSet
    
    Throws:
    
    java.lang.IllegalArgumentException - if the initial capacity is negative, or if the load factor is nonpositive.
  - WeakSet
```
public WeakSet(int initialCapacity)
```
    Constructs a new, empty WeakSet with the given initial capacity and the default load factor (0.75).
    
    Parameters:
    
    initialCapacity - The initial capacity of the WeakSet
    
    Throws:
    
    java.lang.IllegalArgumentException - if the initial capacity is negative
  - WeakSet
```
public WeakSet()
```
    Constructs a new, empty WeakSet with the default initial capacity (16) and load factor (0.75).
  - WeakSet
```
public WeakSet(java.util.Collection<? extends E> s)
```
    Constructs a new WeakSet with the same mappings as the specified map. The WeakSet is created with the default load factor (0.75) and an initial capacity sufficient to hold the mappings in the specified map.
    
    Parameters:
    
    s - the map whose mappings are to be placed in this map
    
    Throws:
    
    java.lang.NullPointerException - if the specified map is null
- Method Detail
  - clear
```
public void clear()
```
    Overrides:
    
    clear in class java.util.AbstractCollection<E>
  - size
```
public int size()
```
    Specified by:
    
    size in class java.util.AbstractCollection<E>
  - isEmpty
```
public boolean isEmpty()
```
    Overrides:
    
    isEmpty in class java.util.AbstractCollection<E>
  - contains
```
public boolean contains(java.lang.Object o)
```
    Overrides:
    
    contains in class java.util.AbstractCollection<E>
  - remove
```
public boolean remove(java.lang.Object o)
```
    Overrides:
    
    remove in class java.util.AbstractCollection<E>
  - resize
```
public void resize(int newCapacity)
```
    compact set if it is empty by setting new capacity
    
    Parameters:
    
    newCapacity - new capacity
    
    Since:
    
    8.11
  - add
```
public boolean add(E e)
```
    Overrides:
    
    add in class java.util.AbstractCollection<E>
    
    See Also:
    
    putIfAbsent(E)
  - iterator
```
public java.util.Iterator<E> iterator()
```
    Specified by:
    
    iterator in class java.util.AbstractCollection<E>
  - toArray
```
public java.lang.Object[] toArray()
```
    Overrides:
    
    toArray in class java.util.AbstractCollection<E>
  - toArray
```
public <T> T[] toArray(T[] a)
```
    Overrides:
    
    toArray in class java.util.AbstractCollection<E>
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.util.AbstractCollection<E>
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.util.AbstractSet<E>
  - equals
```
public boolean equals(java.lang.Object o)
```
    Overrides:
    
    equals in class java.util.AbstractSet<E>
  - containsAll
```
public boolean containsAll(java.util.Collection<?> c)
```
    Overrides:
    
    containsAll in class java.util.AbstractCollection<E>
  - removeAll
```
public boolean removeAll(java.util.Collection<?> c)
```
    Overrides:
    
    removeAll in class java.util.AbstractSet<E>
  - retainAll
```
public boolean retainAll(java.util.Collection<?> c)
```
    Overrides:
    
    retainAll in class java.util.AbstractCollection<E>
  - putIfAbsent
```
public E putIfAbsent(E e)
```
    Put object in this set if equal one is not yet in set. Returns previous set entry if equal object is already in set.
```
  WeakSet<MyClass> set = new WeakSet<MyClass>();
  ...
  MyClass sharedValue = set.putIfAbsent(new MyClass("abc));
 
```
    Parameters:
    
    e - object to put in set.
    
    Returns:
    
    the previous set entry equals with e, or passed object e if there were not entry in set.
    
    Since:
    
    8.11
  - clone
```
public java.lang.Object clone()
```
    Overrides:
    
    clone in class java.lang.Object

Class WeakSet<E>

Constructor Summary

Method Summary

Methods inherited from class java.util.AbstractCollection

Methods inherited from interface java.util.Collection

Methods inherited from interface java.lang.Iterable

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Set

Constructor Detail

WeakSet

WeakSet

WeakSet

WeakSet

Method Detail

clear

size

isEmpty

contains

remove

resize

add

iterator

toArray

toArray

toString

hashCode

equals

containsAll

removeAll

retainAll

putIfAbsent

clone