 Known Direct Subclasses
| HashSet<E> |
HashSet is an implementation of a Set. |
| TreeSet<E> |
TreeSet is an implementation of SortedSet. |
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Known Indirect Subclasses
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Class Overview
An AbstractSet is an abstract implementation of the Set interface. This
implementation does not support adding. A subclass must implement the
abstract methods iterator() and size().
Summary
| Protected Constructors |
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AbstractSet()
Constructs a new instance of this AbstractSet.
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| Public Methods |
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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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[Expand]
Inherited Methods |
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From class
java.util.AbstractCollection
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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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Object[]
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toArray()
Returns a new array containing all elements contained in this
ArrayList.
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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
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boolean
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equals(Object obj)
Indicates whether some other object is "equal to" this one.
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final
Class<?>
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getClass()
Returns the runtime class of an object.
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int
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hashCode()
Returns a hash code value for the object.
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final
void
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notify()
Wakes up a single thread that is waiting on this object's monitor.
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final
void
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notifyAll()
Wakes up all threads that are waiting on this object's monitor.
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String
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toString()
Returns a string representation of the object.
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final
void
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wait(long timeout, int nanos)
Causes current thread to wait until another thread invokes the
notify() method or the
notifyAll() method for this object, or some other
thread interrupts the current thread, or a certain amount of real time has
elapsed. |
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final
void
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wait(long timeout)
Causes current thread to wait until either another thread invokes the
notify() method or the
notifyAll() method for this object, or a specified
amount of time has elapsed. |
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final
void
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wait()
Causes current thread to wait until another thread invokes the
notify() method or the
notifyAll() method for this object. |
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From interface
java.lang.Iterable
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From interface
java.util.Collection
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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[] a)
Returns an array containing all of the elements in this collection; the
runtime type of the returned array is that of the specified array.
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abstract
Object[]
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toArray()
Returns an array containing all of the elements in this collection.
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From interface
java.util.Set
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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
Object[]
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toArray()
Returns an array containing all elements contained in this set.
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Protected Constructors
protected
AbstractSet
()
Constructs a new instance of this AbstractSet.
Public Methods
public
boolean
equals
(Object object)
Compares the specified object to this Set and returns true if they are equal.
The object must be an instance of Set and contain the same objects.
Parameters
| object |
the object to compare with this set. |
Returns
true if the specified object is equal to this set,
false otherwise
public
int
hashCode
()
Returns the hash code for this set. Two set which are equal must return the
same value. This implementation calculates the hash code by adding each
element's hash code.
Returns
- the hash code of this set.
public
boolean
removeAll
(Collection<?> collection)
Removes all occurrences in this collection which are contained in the
specified collection.
Parameters
| collection |
the collection of objects to remove. |
Returns
true if this collection was modified, false
otherwise.