Package jadex.collection
Class IdentityHashSet<T>
java.lang.Object
jadex.collection.IdentityHashSet<T>
- All Implemented Interfaces:
Iterable<T>
,Collection<T>
,Set<T>
A set based on identity comparison.
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Field Summary
Fields -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionboolean
Adds the specified element to this set if it is not already present (optional operation).boolean
addAll
(Collection<? extends T> c) Adds all of the elements in the specified collection to this set if they're not already present (optional operation).void
clear()
Removes all of the elements from this set (optional operation).boolean
Returns true if this set contains the specified element.boolean
containsAll
(Collection<?> c) Returns true if this set contains all of the elements of the specified collection.boolean
Compares the specified object with this set for equality.int
hashCode()
Returns the hash code value for this set.boolean
isEmpty()
Returns true if this set contains no elements.iterator()
Returns an iterator over the elements in this set.boolean
Removes the specified element from this set if it is present (optional operation).boolean
removeAll
(Collection<?> c) Removes from this set all of its elements that are contained in the specified collection (optional operation).boolean
retainAll
(Collection<?> c) Retains only the elements in this set that are contained in the specified collection (optional operation).int
size()
Returns the number of elements in this set (its cardinality).Object[]
toArray()
Returns an array containing all of the elements in this set.<E> E[]
toArray
(E[] a) Returns an array containing all of the elements in this set; the runtime type of the returned array is that of the specified array.toString()
Create a string representation.Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface java.util.Collection
parallelStream, removeIf, stream, toArray
Methods inherited from interface java.util.Set
spliterator
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Field Details
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map
The backing map.
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Constructor Details
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IdentityHashSet
public IdentityHashSet()Create a new identity hash set.
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Method Details
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size
public int size()Returns the number of elements in this set (its cardinality). If this set contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE. -
isEmpty
public boolean isEmpty()Returns true if this set contains no elements. -
contains
Returns true if this set contains the specified element. More formally, returns true if and only if this set contains an elemente
such that(o==null ? e==null : o.equals(e))
.- Specified by:
contains
in interfaceCollection<T>
- Specified by:
contains
in interfaceSet<T>
- Parameters:
o
- element whose presence in this set is to be tested.- Returns:
- true if this set contains the specified element.
- Throws:
ClassCastException
- if the type of the specified element is incompatible with this set (optional).NullPointerException
- if the specified element is null and this set does not support null elements (optional).
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iterator
Returns an iterator over the elements in this set. The elements are returned in no particular order (unless this set is an instance of some class that provides a guarantee). -
toArray
Returns an array containing all of the elements in this set. Obeys the general contract of the Collection.toArray method. -
toArray
public <E> E[] toArray(E[] a) Returns an array containing all of the elements in this set; the runtime type of the returned array is that of the specified array. Obeys the general contract of the Collection.toArray(Object[]) method.- Specified by:
toArray
in interfaceCollection<T>
- Specified by:
toArray
in interfaceSet<T>
- Parameters:
a
- the array into which the elements of this set are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose.- Returns:
- an array containing the elements of this set.
- Throws:
ArrayStoreException
- the runtime type of a is not a supertype of the runtime type of every element in this set.NullPointerException
- if the specified array is null.
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add
Adds the specified element to this set if it is not already present (optional operation). More formally, adds the specified element,o
, to this set if this set contains no elemente
such that(o==null ? e==null : o.equals(e))
. If this set already contains the specified element, the call leaves this set unchanged and returns false. In combination with the restriction on constructors, this ensures that sets never contain duplicate elements.The stipulation above does not imply that sets must accept all elements; sets may refuse to add any particular element, including null, and throwing an exception, as described in the specification for Collection.add. Individual set implementations should clearly document any restrictions on the the elements that they may contain.
- Specified by:
add
in interfaceCollection<T>
- Specified by:
add
in interfaceSet<T>
- Parameters:
o
- element to be added to this set.- Returns:
- true if this set did not already contain the specified element.
- Throws:
UnsupportedOperationException
- if the add method is not supported by this set.ClassCastException
- if the class of the specified element prevents it from being added to this set.NullPointerException
- if the specified element is null and this set does not support null elements.IllegalArgumentException
- if some aspect of the specified element prevents it from being added to this set.
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remove
Removes the specified element from this set if it is present (optional operation). More formally, removes an elemente
such that(o==null ? e==null : o.equals(e))
, if the set contains such an element. Returns true if the set contained the specified element (or equivalently, if the set changed as a result of the call). (The set will not contain the specified element once the call returns.)- Specified by:
remove
in interfaceCollection<T>
- Specified by:
remove
in interfaceSet<T>
- Parameters:
o
- object to be removed from this set, if present.- Returns:
- true if the set contained the specified element.
- Throws:
ClassCastException
- if the type of the specified element is incompatible with this set (optional).NullPointerException
- if the specified element is null and this set does not support null elements (optional).UnsupportedOperationException
- if the remove method is not supported by this set.
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containsAll
Returns true if this set contains all of the elements of the specified collection. If the specified collection is also a set, this method returns true if it is a subset of this set.- Specified by:
containsAll
in interfaceCollection<T>
- Specified by:
containsAll
in interfaceSet<T>
- Parameters:
c
- collection to be checked for containment in this set.- Returns:
- true if this set contains all of the elements of the specified collection.
- Throws:
ClassCastException
- if the types of one or more elements in the specified collection are incompatible with this set (optional).NullPointerException
- if the specified collection contains one or more null elements and this set does not support null elements (optional).NullPointerException
- if the specified collection is null.- See Also:
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addAll
Adds all of the elements in the specified collection to this set if they're not already present (optional operation). If the specified collection is also a set, the addAll operation effectively modifies this set so that its value is the union of the two sets. The behavior of this operation is unspecified if the specified collection is modified while the operation is in progress.- Specified by:
addAll
in interfaceCollection<T>
- Specified by:
addAll
in interfaceSet<T>
- Parameters:
c
- collection whose elements are to be added to this set.- Returns:
- true if this set changed as a result of the call.
- Throws:
UnsupportedOperationException
- if the addAll method is not supported by this set.ClassCastException
- if the class of some element of the specified collection prevents it from being added to this set.NullPointerException
- if the specified collection contains one or more null elements and this set does not support null elements, or if the specified collection is null.IllegalArgumentException
- if some aspect of some element of the specified collection prevents it from being added to this set.- See Also:
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retainAll
Retains only the elements in this set that are contained in the specified collection (optional operation). In other words, removes from this set all of its elements that are not contained in the specified collection. If the specified collection is also a set, this operation effectively modifies this set so that its value is the intersection of the two sets.- Specified by:
retainAll
in interfaceCollection<T>
- Specified by:
retainAll
in interfaceSet<T>
- Parameters:
c
- collection that defines which elements this set will retain.- Returns:
- true if this collection changed as a result of the call.
- Throws:
UnsupportedOperationException
- if the retainAll method is not supported by this Collection.ClassCastException
- if the types of one or more elements in this set are incompatible with the specified collection (optional).NullPointerException
- if this set contains a null element and the specified collection does not support null elements (optional).NullPointerException
- if the specified collection is null.- See Also:
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removeAll
Removes from this set all of its elements that are contained in the specified collection (optional operation). If the specified collection is also a set, this operation effectively modifies this set so that its value is the asymmetric set difference of the two sets.- Specified by:
removeAll
in interfaceCollection<T>
- Specified by:
removeAll
in interfaceSet<T>
- Parameters:
c
- collection that defines which elements will be removed from this set.- Returns:
- true if this set changed as a result of the call.
- Throws:
UnsupportedOperationException
- if the removeAll method is not supported by this Collection.ClassCastException
- if the types of one or more elements in this set are incompatible with the specified collection (optional).NullPointerException
- if this set contains a null element and the specified collection does not support null elements (optional).NullPointerException
- if the specified collection is null.- See Also:
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clear
public void clear()Removes all of the elements from this set (optional operation). This set will be empty after this call returns (unless it throws an exception).- Specified by:
clear
in interfaceCollection<T>
- Specified by:
clear
in interfaceSet<T>
- Throws:
UnsupportedOperationException
- if the clear method is not supported by this set.
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equals
Compares the specified object with this set for equality. Returns true if the specified object is also a set, the two sets have the same size, and every member of the specified set is contained in this set (or equivalently, every member of this set is contained in the specified set). This definition ensures that the equals method works properly across different implementations of the set interface. -
hashCode
public int hashCode()Returns the hash code value for this set. The hash code of a set is defined to be the sum of the hash codes of the elements in the set, where the hashcode of a null element is defined to be zero. This ensures thats1.equals(s2)
implies thats1.hashCode()==s2.hashCode()
for any two setss1
ands2
, as required by the general contract of the Object.hashCode method. -
toString
Create a string representation.
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