Class Overview
LinkedHashSet is a variant of HashSet. Its entries are kept in a doubly-linked list. The iteration order is the order in which entries were inserted.
Null elements are allowed, and all the optional Set operations are supported.
Like HashSet, LinkedHashSet is not thread safe, so access by multiple threads must be synchronized by an external mechanism such as synchronizedSet(Set)
.
Summary
Public Constructors |
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LinkedHashSet()
Constructs a new empty instance of
LinkedHashSet .
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LinkedHashSet(int capacity)
Constructs a new instance of
LinkedHashSet with the specified capacity.
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LinkedHashSet(int capacity, float loadFactor)
Constructs a new instance of
LinkedHashSet with the specified capacity and load factor.
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LinkedHashSet(
Collection<? extends E> collection)
Constructs a new instance of
LinkedHashSet containing the unique elements in the specified collection.
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[Expand]
Inherited Methods
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From class java.util.HashSet
boolean
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add(E object)
Adds the specified object to this
HashSet if not already present.
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void
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clear()
Removes all elements from this
HashSet , leaving it empty.
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Object
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clone()
Returns a new
HashSet with the same elements and size as this
HashSet .
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boolean
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contains(
Object object)
Searches this
HashSet for the specified object.
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boolean
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isEmpty()
Returns true if this
HashSet has no elements, false otherwise.
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Iterator<E>
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iterator()
Returns an Iterator on the elements of this
HashSet .
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boolean
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remove(
Object object)
Removes the specified object from this
HashSet .
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int
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size()
Returns the number of elements in this
HashSet .
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From class java.util.AbstractSet
boolean
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equals(
Object object)
Compares the specified object to this Set and returns true if they are equal.
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int
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hashCode()
Returns the hash code for this set.
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boolean
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removeAll(
Collection<?> collection)
Removes all occurrences in this collection which are contained in the specified collection.
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From class java.util.AbstractCollection
boolean
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add(E object)
Attempts to add
object to the contents of this
Collection (optional).
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boolean
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addAll(
Collection<? extends E> collection)
Attempts to add all of the objects contained in
collection to the contents of this
Collection (optional).
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void
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clear()
Removes all elements from this
Collection , leaving it empty (optional).
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boolean
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contains(
Object object)
Tests whether this
Collection contains the specified object.
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boolean
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containsAll(
Collection<?> collection)
Tests whether this
Collection contains all objects contained in the specified
Collection .
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boolean
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isEmpty()
Returns if this
Collection contains no elements.
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abstract
Iterator<E>
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iterator()
Returns an instance of
Iterator that may be used to access the objects contained by this
Collection .
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boolean
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remove(
Object object)
Removes one instance of the specified object from this
Collection if one is contained (optional).
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boolean
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removeAll(
Collection<?> collection)
Removes all occurrences in this
Collection of each object in the specified
Collection (optional).
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boolean
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retainAll(
Collection<?> collection)
Removes all objects from this
Collection that are not also found in the
Collection passed (optional).
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abstract int
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size()
Returns a count of how many objects this
Collection contains.
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<T> T[]
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toArray(T[] contents)
Returns an array containing all elements contained in this
Collection .
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Object[]
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toArray()
Returns a new array containing all elements contained in this
Collection .
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String
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toString()
Returns the string representation of this
Collection .
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From class java.lang.Object
Object
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clone()
Creates and returns a copy of this
Object .
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boolean
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equals(
Object o)
Compares this instance with the specified object and indicates if they are equal.
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void
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finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.
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final
Class<?>
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getClass()
Returns the unique instance of
Class that represents this object's class.
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int
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hashCode()
Returns an integer hash code for this object.
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final void
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notify()
Causes a thread which is waiting on this object's monitor (by means of calling one of the
wait() methods) to be woken up.
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final void
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notifyAll()
Causes all threads which are waiting on this object's monitor (by means of calling one of the
wait() methods) to be woken up.
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String
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toString()
Returns a string containing a concise, human-readable description of this object.
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final void
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wait()
Causes the calling thread to wait until another thread calls the
notify() or
notifyAll() method of this object.
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final void
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wait(long millis, int nanos)
Causes the calling thread to wait until another thread calls the
notify() or
notifyAll() method of this object or until the specified timeout expires.
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final void
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wait(long millis)
Causes the calling thread to wait until another thread calls the
notify() or
notifyAll() method of this object or until the specified timeout expires.
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From interface java.lang.Iterable
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From interface java.util.Collection
abstract boolean
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add(E object)
Attempts to add
object to the contents of this
Collection (optional).
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abstract boolean
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addAll(
Collection<? extends E> collection)
Attempts to add all of the objects contained in
Collection to the contents of this
Collection (optional).
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abstract void
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clear()
Removes all elements from this
Collection , leaving it empty (optional).
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abstract boolean
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contains(
Object object)
Tests whether this
Collection contains the specified object.
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abstract boolean
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containsAll(
Collection<?> collection)
Tests whether this
Collection contains all objects contained in the specified
Collection .
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abstract boolean
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equals(
Object object)
Compares the argument to the receiver, and returns true if they represent the
same object using a class specific comparison.
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abstract int
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hashCode()
Returns an integer hash code for the receiver.
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abstract boolean
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isEmpty()
Returns if this
Collection contains no elements.
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abstract
Iterator<E>
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iterator()
Returns an instance of
Iterator that may be used to access the objects contained by this
Collection .
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abstract boolean
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remove(
Object object)
Removes one instance of the specified object from this
Collection if one is contained (optional).
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abstract boolean
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removeAll(
Collection<?> collection)
Removes all occurrences in this
Collection of each object in the specified
Collection (optional).
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abstract boolean
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retainAll(
Collection<?> collection)
Removes all objects from this
Collection that are not also found in the
Collection passed (optional).
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abstract int
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size()
Returns a count of how many objects this
Collection contains.
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abstract <T> T[]
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toArray(T[] array)
Returns an array containing all elements contained in this
Collection .
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abstract
Object[]
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toArray()
Returns a new array containing all elements contained in this
Collection .
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From interface java.util.Set
abstract boolean
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add(E object)
Adds the specified object to this set.
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abstract boolean
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addAll(
Collection<? extends E> collection)
Adds the objects in the specified collection which do not exist yet in this set.
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abstract void
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clear()
Removes all elements from this set, leaving it empty.
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abstract boolean
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contains(
Object object)
Searches this set for the specified object.
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abstract boolean
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containsAll(
Collection<?> collection)
Searches this set for all objects in the specified collection.
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abstract boolean
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equals(
Object object)
Compares the specified object to this set, and returns true if they represent the
same object using a class specific comparison.
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abstract int
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hashCode()
Returns the hash code for this set.
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abstract boolean
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isEmpty()
Returns true if this set has no elements.
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abstract
Iterator<E>
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iterator()
Returns an iterator on the elements of this set.
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abstract boolean
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remove(
Object object)
Removes the specified object from this set.
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abstract boolean
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removeAll(
Collection<?> collection)
Removes all objects in the specified collection from this set.
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abstract boolean
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retainAll(
Collection<?> collection)
Removes all objects from this set that are not contained in the specified collection.
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abstract int
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size()
Returns the number of elements in this set.
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abstract <T> T[]
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toArray(T[] array)
Returns an array containing all elements contained in this set.
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abstract
Object[]
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toArray()
Returns an array containing all elements contained in this set.
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Public Constructors
public LinkedHashSet ()
Constructs a new empty instance of LinkedHashSet
.
public LinkedHashSet (int capacity)
Constructs a new instance of LinkedHashSet
with the specified capacity.
Parameters
capacity |
the initial capacity of this LinkedHashSet . |
public LinkedHashSet (int capacity, float loadFactor)
Constructs a new instance of LinkedHashSet
with the specified capacity and load factor.
Parameters
capacity |
the initial capacity. |
loadFactor |
the initial load factor. |
public LinkedHashSet (Collection<? extends E> collection)
Constructs a new instance of LinkedHashSet
containing the unique elements in the specified collection.
Parameters
collection |
the collection of elements to add. |