Class AbstractMapMultiSet<E>
- Type Parameters:
E- the type held in the multiset.
- All Implemented Interfaces:
Iterable<E>,Collection<E>,MultiSet<E>
- Direct Known Subclasses:
HashMultiSet
MultiSet interface to simplify the
creation of subclass implementations.
Subclasses specify a Map implementation to use as the internal storage. The map will be used to map multiset elements to a number; the number represents the number of occurrences of that element in the multiset.
- Since:
- 4.1
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionprotected static classInner class EntrySetIterator.protected static classInner class MultiSetEntry.protected static classMutable integer class for storing the data.protected static classInner class UniqueSetIterator.Nested classes/interfaces inherited from class org.apache.commons.collections4.multiset.AbstractMultiSet
AbstractMultiSet.AbstractEntry<E>, AbstractMultiSet.EntrySet<E>, AbstractMultiSet.UniqueSet<E>Nested classes/interfaces inherited from interface org.apache.commons.collections4.MultiSet
MultiSet.Entry<E> -
Constructor Summary
ConstructorsModifierConstructorDescriptionprotectedConstructor needed for subclass serialization.protectedConstructor that assigns the specified Map as the backing store. -
Method Summary
Modifier and TypeMethodDescriptionintAdds a number of occurrences of the specified object to the MultiSet.voidclear()Clears the multiset by clearing the underlying map.booleanDetermines if the multiset contains the given element by checking if the underlying map contains the element as a key.protected Iterator<MultiSet.Entry<E>> Creates an entry set iterator.Creates a unique set iterator.protected voidReads the multiset in using a custom routine.protected voidWrites the multiset out using a custom routine.booleanCompares this MultiSet to another object.intGets the number of occurrence of the given element in this multiset by looking up its count in the underlying map.protected Map<E, AbstractMapMultiSet.MutableInteger> getMap()Gets the map that backs this multiset.inthashCode()Gets a hash code for the MultiSet compatible with the definition of equals.booleanisEmpty()Returns true if the underlying map is empty.iterator()Gets an iterator over the multiset elements.intRemoves a number of occurrences of the specified object from the MultiSet.protected voidSets the map being wrapped.intsize()Returns the number of elements in this multiset.Object[]toArray()Returns an array of all of this multiset's elements.<T> T[]toArray(T[] array) Returns an array of all of this multiset's elements.protected intReturns the number of unique elements in this multiset.Methods inherited from class org.apache.commons.collections4.multiset.AbstractMultiSet
add, createEntrySet, createUniqueSet, entrySet, remove, removeAll, setCount, toString, uniqueSetMethods inherited from class java.util.AbstractCollection
addAll, containsAll, retainAllMethods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, waitMethods inherited from interface java.util.Collection
addAll, parallelStream, removeIf, spliterator, streamMethods inherited from interface org.apache.commons.collections4.MultiSet
containsAll, retainAll
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Constructor Details
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AbstractMapMultiSet
protected AbstractMapMultiSet()Constructor needed for subclass serialization. -
AbstractMapMultiSet
Constructor that assigns the specified Map as the backing store. The map must be empty and non-null.- Parameters:
map- the map to assign
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Method Details
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add
Description copied from interface:MultiSetAdds a number of occurrences of the specified object to the MultiSet.If the object is already in the
MultiSet.uniqueSet()then increment its count as reported byMultiSet.getCount(Object). Otherwise, add it to theMultiSet.uniqueSet()and report its count asoccurrences.- Specified by:
addin interfaceMultiSet<E>- Overrides:
addin classAbstractMultiSet<E>- Parameters:
object- the object to addoccurrences- the number of occurrences to add, may be zero, in which case no change is made to the multiset- Returns:
- the number of occurrences of the object in the multiset before this operation; possibly zero
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clear
Clears the multiset by clearing the underlying map.- Specified by:
clearin interfaceCollection<E>- Overrides:
clearin classAbstractMultiSet<E>
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contains
Determines if the multiset contains the given element by checking if the underlying map contains the element as a key.- Specified by:
containsin interfaceCollection<E>- Overrides:
containsin classAbstractMultiSet<E>- Parameters:
object- the object to search for- Returns:
- true if the multiset contains the given element
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createEntrySetIterator
Description copied from class:AbstractMultiSetCreates an entry set iterator. Subclasses can override this to return iterators with different properties.- Specified by:
createEntrySetIteratorin classAbstractMultiSet<E>- Returns:
- the entrySet iterator
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createUniqueSetIterator
Description copied from class:AbstractMultiSetCreates a unique set iterator. Subclasses can override this to return iterators with different properties.- Overrides:
createUniqueSetIteratorin classAbstractMultiSet<E>- Returns:
- the uniqueSet iterator
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doReadObject
Reads the multiset in using a custom routine.- Overrides:
doReadObjectin classAbstractMultiSet<E>- Parameters:
in- the input stream- Throws:
IOException- any of the usual I/O related exceptionsClassNotFoundException- if the stream contains an object which class cannot be loadedClassCastException- if the stream does not contain the correct objects
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doWriteObject
Writes the multiset out using a custom routine.- Overrides:
doWriteObjectin classAbstractMultiSet<E>- Parameters:
out- the output stream- Throws:
IOException- any of the usual I/O related exceptions
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equals
Description copied from interface:MultiSetCompares this MultiSet to another object.This MultiSet equals another object if it is also a MultiSet that contains the same number of occurrences of the same elements.
- Specified by:
equalsin interfaceCollection<E>- Specified by:
equalsin interfaceMultiSet<E>- Overrides:
equalsin classAbstractMultiSet<E>- Parameters:
object- the object to compare to- Returns:
- true if equal
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getCount
Gets the number of occurrence of the given element in this multiset by looking up its count in the underlying map. -
getMap
Gets the map that backs this multiset. Not intended for interactive use outside of subclasses.- Returns:
- the map being used by the MultiSet
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hashCode
Description copied from interface:MultiSetGets a hash code for the MultiSet compatible with the definition of equals. The hash code is defined as the sum total of a hash code for each element. The per element hash code is defined as(e==null ? 0 : e.hashCode()) ^ noOccurrences).- Specified by:
hashCodein interfaceCollection<E>- Specified by:
hashCodein interfaceMultiSet<E>- Overrides:
hashCodein classAbstractMultiSet<E>- Returns:
- the hash code of the MultiSet
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isEmpty
Returns true if the underlying map is empty.- Specified by:
isEmptyin interfaceCollection<E>- Overrides:
isEmptyin classAbstractCollection<E>- Returns:
- true if multiset is empty
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iterator
Gets an iterator over the multiset elements. Elements present in the MultiSet more than once will be returned repeatedly. -
remove
Description copied from interface:MultiSetRemoves a number of occurrences of the specified object from the MultiSet.If the number of occurrences to remove is greater than the actual number of occurrences in the multiset, the object will be removed from the multiset.
- Specified by:
removein interfaceMultiSet<E>- Overrides:
removein classAbstractMultiSet<E>- Parameters:
object- the object to removeoccurrences- the number of occurrences to remove, may be zero, in which case no change is made to the multiset- Returns:
- the number of occurrences of the object in the multiset before the operation; possibly zero
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setMap
Sets the map being wrapped.Note: this method should only be used during deserialization
- Parameters:
map- the map to wrap
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size
Returns the number of elements in this multiset.- Specified by:
sizein interfaceCollection<E>- Specified by:
sizein interfaceMultiSet<E>- Overrides:
sizein classAbstractMultiSet<E>- Returns:
- current size of the multiset
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toArray
Returns an array of all of this multiset's elements.- Specified by:
toArrayin interfaceCollection<E>- Overrides:
toArrayin classAbstractCollection<E>- Returns:
- an array of all of this multiset's elements
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toArray
Returns an array of all of this multiset's elements. If the input array has more elements than are in the multiset, trailing elements will be set to null.- Specified by:
toArrayin interfaceCollection<E>- Overrides:
toArrayin classAbstractCollection<E>- Type Parameters:
T- the type of the array elements- Parameters:
array- the array to populate- Returns:
- an array of all of this multiset's elements
- Throws:
ArrayStoreException- if the runtime type of the specified array is not a supertype of the runtime type of the elements in this listNullPointerException- if the specified array is null
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uniqueElements
Description copied from class:AbstractMultiSetReturns the number of unique elements in this multiset.- Specified by:
uniqueElementsin classAbstractMultiSet<E>- Returns:
- the number of unique elements
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