Package com.google.common.collect

Class TreeMultiset<E extends @Nullable Object>

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean add​(E element)
      Adds a single occurrence of the specified element to this multiset.
      int add​(E element, int occurrences)
      Adds a number of occurrences of an element to this multiset.
      boolean addAll​(Collection<? extends E> elementsToAdd)
      void clear()  
      Comparator<? super E> comparator()
      Returns the comparator that orders this multiset, or Ordering.natural() if the natural ordering of the elements is used.
      boolean contains​(@Nullable Object element)
      Determines whether this multiset contains the specified element.
      int count​(@Nullable Object element)
      Returns the number of occurrences of an element in this multiset (the count of the element).
      static <E extends Comparable>
      TreeMultiset<E>      		 create()
      Creates a new, empty multiset, sorted according to the elements' natural order.
      static <E extends @Nullable Object>
      TreeMultiset<E>      		 create​(@Nullable Comparator<? super E> comparator)
      Creates a new, empty multiset, sorted according to the specified comparator.
      static <E extends Comparable>
      TreeMultiset<E>      		 create​(Iterable<? extends E> elements)
      Creates an empty multiset containing the given initial elements, sorted according to the elements' natural order.
      SortedMultiset<E> descendingMultiset()
      Returns a descending view of this multiset.
      NavigableSet<E> elementSet()
      Returns the set of distinct elements contained in this multiset.
      Set<Multiset.Entry<E>> entrySet()
      Returns a view of the contents of this multiset, grouped into Multiset.Entry instances, each providing an element of the multiset and the count of that element.
      boolean equals​(@Nullable Object object)
      Compares the specified object with this multiset for equality.
      @Nullable Multiset.Entry<E> firstEntry()
      Returns the entry of the first element in this multiset, or null if this multiset is empty.
      void forEachEntry​(ObjIntConsumer<? super E> action)
      Runs the specified action for each distinct element in this multiset, and the number of occurrences of that element.
      int hashCode()
      Returns the hash code for this multiset.
      SortedMultiset<E> headMultiset​(E upperBound, BoundType boundType)
      Returns a view of this multiset restricted to the elements less than upperBound, optionally including upperBound itself.
      boolean isEmpty()  
      Iterator<E> iterator()
      @Nullable Multiset.Entry<E> lastEntry()
      Returns the entry of the last element in this multiset, or null if this multiset is empty.
      @Nullable Multiset.Entry<E> pollFirstEntry()
      Returns and removes the entry associated with the lowest element in this multiset, or returns null if this multiset is empty.
      @Nullable Multiset.Entry<E> pollLastEntry()
      Returns and removes the entry associated with the greatest element in this multiset, or returns null if this multiset is empty.
      boolean remove​(@Nullable Object element)
      Removes a single occurrence of the specified element from this multiset, if present.
      int remove​(@Nullable Object element, int occurrences)
      Removes a number of occurrences of the specified element from this multiset.
      boolean removeAll​(Collection<?> elementsToRemove)
      boolean retainAll​(Collection<?> elementsToRetain)
      int setCount​(E element, int count)
      Adds or removes the necessary occurrences of an element such that the element attains the desired count.
      boolean setCount​(E element, int oldCount, int newCount)
      Conditionally sets the count of an element to a new value, as described in Multiset.setCount(Object, int), provided that the element has the expected current count.
      int size()
      Returns the total number of all occurrences of all elements in this multiset.
      SortedMultiset<E> subMultiset​(E fromElement, BoundType fromBoundType, E toElement, BoundType toBoundType)
      Returns a view of this multiset restricted to the range between lowerBound and upperBound.
      SortedMultiset<E> tailMultiset​(E lowerBound, BoundType boundType)
      Returns a view of this multiset restricted to the elements greater than lowerBound, optionally including lowerBound itself.
      String toString()

    • Method Detail

      • create

        public static <E extends Comparable> TreeMultiset<E> create()
        Creates a new, empty multiset, sorted according to the elements' natural order. All elements inserted into the multiset must implement the Comparable interface. Furthermore, all such elements must be mutually comparable: e1.compareTo(e2) must not throw a ClassCastException for any elements e1 and e2 in the multiset. If the user attempts to add an element to the multiset that violates this constraint (for example, the user attempts to add a string element to a set whose elements are integers), the add(Object) call will throw a ClassCastException.

        The type specification is <E extends Comparable>, instead of the more specific <E extends Comparable<? super E>>, to support classes defined without generics.

      • create

        public static <E extends @Nullable Object> TreeMultiset<E> create​(@Nullable Comparator<? super E> comparator)
        Creates a new, empty multiset, sorted according to the specified comparator. All elements inserted into the multiset must be mutually comparable by the specified comparator: comparator.compare(e1, e2) must not throw a ClassCastException for any elements e1 and e2 in the multiset. If the user attempts to add an element to the multiset that violates this constraint, the add(Object) call will throw a ClassCastException.
        Parameters:
        comparator - the comparator that will be used to sort this multiset. A null value indicates that the elements' natural ordering should be used.

      • create

        public static <E extends Comparable> TreeMultiset<E> create​(Iterable<? extends E> elements)
        Creates an empty multiset containing the given initial elements, sorted according to the elements' natural order.

        This implementation is highly efficient when elements is itself a Multiset.

        The type specification is <E extends Comparable>, instead of the more specific <E extends Comparable<? super E>>, to support classes defined without generics.

      • size

        public int size()
        Description copied from interface: Multiset
        Returns the total number of all occurrences of all elements in this multiset.

        Note: this method does not return the number of distinct elements in the multiset, which is given by entrySet().size().

        Specified by:
        size in interface Collection<E extends @Nullable Object>
        Specified by:
        size in interface Multiset<E extends @Nullable Object>
        Specified by:
        size in class AbstractCollection<E extends @Nullable Object>

      • add

        @CanIgnoreReturnValue
public int add​(E element,
               int occurrences)
        Description copied from interface: Multiset
        Adds a number of occurrences of an element to this multiset. Note that if occurrences == 1, this method has the identical effect to Multiset.add(Object). This method is functionally equivalent (except in the case of overflow) to the call addAll(Collections.nCopies(element, occurrences)), which would presumably perform much more poorly.
        Specified by:
        add in interface Multiset<E extends @Nullable Object>
        Parameters:
        element - the element to add occurrences of; may be null only if explicitly allowed by the implementation
        occurrences - the number of occurrences of the element to add. May be zero, in which case no change will be made.
        Returns:
        the count of the element before the operation; possibly zero

      • remove

        @CanIgnoreReturnValue
public int remove​(@Nullable Object element,
                  int occurrences)
        Description copied from interface: Multiset
        Removes a number of occurrences of the specified element from this multiset. If the multiset contains fewer than this number of occurrences to begin with, all occurrences will be removed. Note that if occurrences == 1, this is functionally equivalent to the call remove(element).
        Specified by:
        remove in interface Multiset<E extends @Nullable Object>
        Parameters:
        element - the element to conditionally remove occurrences of
        occurrences - the number of occurrences of the element to remove. May be zero, in which case no change will be made.
        Returns:
        the count of the element before the operation; possibly zero

      • setCount

        @CanIgnoreReturnValue
public int setCount​(E element,
                    int count)
        Description copied from interface: Multiset
        Adds or removes the necessary occurrences of an element such that the element attains the desired count.
        Specified by:
        setCount in interface Multiset<E extends @Nullable Object>
        Parameters:
        element - the element to add or remove occurrences of; may be null only if explicitly allowed by the implementation
        count - the desired count of the element in this multiset
        Returns:
        the count of the element before the operation; possibly zero

      • setCount

        @CanIgnoreReturnValue
public boolean setCount​(E element,
                        int oldCount,
                        int newCount)
        Description copied from interface: Multiset
        Conditionally sets the count of an element to a new value, as described in Multiset.setCount(Object, int), provided that the element has the expected current count. If the current count is not oldCount, no change is made.
        Specified by:
        setCount in interface Multiset<E extends @Nullable Object>
        Parameters:
        element - the element to conditionally set the count of; may be null only if explicitly allowed by the implementation
        oldCount - the expected present count of the element in this multiset
        newCount - the desired count of the element in this multiset
        Returns:
        true if the condition for modification was met. This implies that the multiset was indeed modified, unless oldCount == newCount.

      • forEachEntry

        public void forEachEntry​(ObjIntConsumer<? super E> action)
        Description copied from interface: Multiset
        Runs the specified action for each distinct element in this multiset, and the number of occurrences of that element. For some Multiset implementations, this may be more efficient than iterating over the Multiset.entrySet() either explicitly or with entrySet().forEach(action).
        Specified by:
        forEachEntry in interface Multiset<E extends @Nullable Object>

      • headMultiset

        public SortedMultiset<E> headMultiset​(E upperBound,
                                      BoundType boundType)
        Description copied from interface: SortedMultiset
        Returns a view of this multiset restricted to the elements less than upperBound, optionally including upperBound itself. The returned multiset is a view of this multiset, so changes to one will be reflected in the other. The returned multiset supports all operations that this multiset supports.

        The returned multiset will throw an IllegalArgumentException on attempts to add elements outside its range.

        Specified by:
        headMultiset in interface SortedMultiset<E extends @Nullable Object>

      • tailMultiset

        public SortedMultiset<E> tailMultiset​(E lowerBound,
                                      BoundType boundType)
        Description copied from interface: SortedMultiset
        Returns a view of this multiset restricted to the elements greater than lowerBound, optionally including lowerBound itself. The returned multiset is a view of this multiset, so changes to one will be reflected in the other. The returned multiset supports all operations that this multiset supports.

        The returned multiset will throw an IllegalArgumentException on attempts to add elements outside its range.

        Specified by:
        tailMultiset in interface SortedMultiset<E extends @Nullable Object>

      • elementSet

        public NavigableSet<E> elementSet()
        Description copied from interface: Multiset
        Returns the set of distinct elements contained in this multiset. The element set is backed by the same data as the multiset, so any change to either is immediately reflected in the other. The order of the elements in the element set is unspecified.

        If the element set supports any removal operations, these necessarily cause all occurrences of the removed element(s) to be removed from the multiset. Implementations are not expected to support the add operations, although this is possible.

        A common use for the element set is to find the number of distinct elements in the multiset: elementSet().size().

        Specified by:
        elementSet in interface Multiset<E extends @Nullable Object>
        Specified by:
        elementSet in interface SortedMultiset<E extends @Nullable Object>
        Returns:
        a view of the set of distinct elements in this multiset

      • pollFirstEntry

        public @Nullable Multiset.Entry<E> pollFirstEntry()
        Description copied from interface: SortedMultiset
        Returns and removes the entry associated with the lowest element in this multiset, or returns null if this multiset is empty.
        Specified by:
        pollFirstEntry in interface SortedMultiset<E extends @Nullable Object>

      • pollLastEntry

        public @Nullable Multiset.Entry<E> pollLastEntry()
        Description copied from interface: SortedMultiset
        Returns and removes the entry associated with the greatest element in this multiset, or returns null if this multiset is empty.
        Specified by:
        pollLastEntry in interface SortedMultiset<E extends @Nullable Object>

      • subMultiset

        public SortedMultiset<E> subMultiset​(E fromElement,
                                     BoundType fromBoundType,
                                     E toElement,
                                     BoundType toBoundType)
        Description copied from interface: SortedMultiset
        Returns a view of this multiset restricted to the range between lowerBound and upperBound. The returned multiset is a view of this multiset, so changes to one will be reflected in the other. The returned multiset supports all operations that this multiset supports.

        The returned multiset will throw an IllegalArgumentException on attempts to add elements outside its range.

        This method is equivalent to tailMultiset(lowerBound, lowerBoundType).headMultiset(upperBound, upperBoundType).

        Specified by:
        subMultiset in interface SortedMultiset<E extends @Nullable Object>

      • contains

        public boolean contains​(@Nullable Object element)
        Description copied from interface: Multiset
        Determines whether this multiset contains the specified element.

        This method refines Collection.contains(java.lang.Object) to further specify that it may not throw an exception in response to element being null or of the wrong type.

        Specified by:
        contains in interface Collection<E extends @Nullable Object>
        Specified by:
        contains in interface Multiset<E extends @Nullable Object>
        Overrides:
        contains in class AbstractCollection<E extends @Nullable Object>
        Parameters:
        element - the element to check for
        Returns:
        true if this multiset contains at least one occurrence of the element

      • add

        @CanIgnoreReturnValue
public final boolean add​(E element)
        Description copied from interface: Multiset
        Adds a single occurrence of the specified element to this multiset.

        This method refines Collection.add(E), which only ensures the presence of the element, to further specify that a successful call must always increment the count of the element, and the overall size of the collection, by one.

        To both add the element and obtain the previous count of that element, use add(element, 1) instead.

        Specified by:
        add in interface Collection<E extends @Nullable Object>
        Specified by:
        add in interface Multiset<E extends @Nullable Object>
        Overrides:
        add in class AbstractCollection<E extends @Nullable Object>
        Parameters:
        element - the element to add one occurrence of; may be null only if explicitly allowed by the implementation
        Returns:
        true always, since this call is required to modify the multiset, unlike other Collection types

      • remove

        @CanIgnoreReturnValue
public final boolean remove​(@Nullable Object element)
        Description copied from interface: Multiset
        Removes a single occurrence of the specified element from this multiset, if present.

        This method refines Collection.remove(java.lang.Object) to further specify that it may not throw an exception in response to element being null or of the wrong type.

        To both remove the element and obtain the previous count of that element, use remove(element, 1) instead.

        Specified by:
        remove in interface Collection<E extends @Nullable Object>
        Specified by:
        remove in interface Multiset<E extends @Nullable Object>
        Overrides:
        remove in class AbstractCollection<E extends @Nullable Object>
        Parameters:
        element - the element to remove one occurrence of
        Returns:
        true if an occurrence was found and removed

      • entrySet

        public Set<Multiset.Entry<E>> entrySet()
        Description copied from interface: Multiset
        Returns a view of the contents of this multiset, grouped into Multiset.Entry instances, each providing an element of the multiset and the count of that element. This set contains exactly one entry for each distinct element in the multiset (thus it always has the same size as the Multiset.elementSet()). The order of the elements in the element set is unspecified.

        The entry set is backed by the same data as the multiset, so any change to either is immediately reflected in the other. However, multiset changes may or may not be reflected in any Entry instances already retrieved from the entry set (this is implementation-dependent). Furthermore, implementations are not required to support modifications to the entry set at all, and the Entry instances themselves don't even have methods for modification. See the specific implementation class for more details on how its entry set handles modifications.

        Specified by:
        entrySet in interface Multiset<E extends @Nullable Object>
        Returns:
        a set of entries representing the data of this multiset

      • equals

        public final boolean equals​(@Nullable Object object)
        Compares the specified object with this multiset for equality. Returns true if the given object is also a multiset and contains equal elements with equal counts, regardless of order.

        This implementation returns true if object is a multiset of the same size and if, for each element, the two multisets have the same count.

        Specified by:
        equals in interface Collection<E extends @Nullable Object>
        Specified by:
        equals in interface Multiset<E extends @Nullable Object>
        Overrides:
        equals in class Object

      • hashCode

        public final int hashCode()
        Returns the hash code for this multiset. This is defined as the sum of 
        
 ((element == null) ? 0 : element.hashCode()) ^ count(element)

        over all distinct elements in the multiset. It follows that a multiset and its entry set always have the same hash code.

        This implementation returns the hash code of Multiset.entrySet().

        Specified by:
        hashCode in interface Collection<E extends @Nullable Object>
        Specified by:
        hashCode in interface Multiset<E extends @Nullable Object>
        Overrides:
        hashCode in class Object