Package com.google.common.collect

Class ForwardingSortedSet<E>

  • All Implemented Interfaces:
    Iterable<E>, Collection<E>, Set<E>, SortedSet<E>
    Direct Known Subclasses:
    ForwardingNavigableSet
    @GwtCompatible
public abstract class ForwardingSortedSet<E>
extends ForwardingSet<E>
implements SortedSet<E>
    A sorted set which forwards all its method calls to another sorted set. Subclasses should override one or more methods to modify the behavior of the backing sorted set as desired per the decorator pattern.

    Warning: The methods of ForwardingSortedSet forward indiscriminately to the methods of the delegate. For example, overriding ForwardingCollection.add(E) alone will not change the behavior of ForwardingCollection.addAll(java.util.Collection<? extends E>), which can lead to unexpected behavior. In this case, you should override addAll as well, either providing your own implementation, or delegating to the provided standardAddAll method.

    default method warning: This class does not forward calls to default methods. Instead, it inherits their default implementations. When those implementations invoke methods, they invoke methods on the ForwardingSortedSet.

    Each of the standard methods, where appropriate, uses the set's comparator (or the natural ordering of the elements, if there is no comparator) to test element equality. As a result, if the comparator is not consistent with equals, some of the standard implementations may violate the Set contract.

    The standard methods and the collection views they return are not guaranteed to be thread-safe, even when all of the methods that they depend on are thread-safe.

    Since:
    2.0
    Author:
    Mike Bostock, Louis Wasserman

    • Constructor Detail

    • Method Detail

      • delegate

        protected abstract SortedSet<E> delegate()
        Description copied from class: ForwardingObject
        Returns the backing delegate instance that methods are forwarded to. Abstract subclasses generally override this method with an abstract method that has a more specific return type, such as ForwardingSet.delegate(). Concrete subclasses override this method to supply the instance being decorated.
        Specified by:
        delegate in class ForwardingSet<E>

      • comparator

        public Comparator<? super E> comparator()
        Description copied from interface: java.util.SortedSet
        Returns the comparator used to order the elements in this set, or null if this set uses the natural ordering of its elements.
        Specified by:
        comparator in interface SortedSet<E>
        Returns:
        the comparator used to order the elements in this set, or null if this set uses the natural ordering of its elements

      • first

        public E first()
        Description copied from interface: java.util.SortedSet
        Returns the first (lowest) element currently in this set.
        Specified by:
        first in interface SortedSet<E>
        Returns:
        the first (lowest) element currently in this set

      • headSet

        public SortedSet<E> headSet(E toElement)
        Description copied from interface: java.util.SortedSet
        Returns a view of the portion of this set whose elements are strictly less than toElement. The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports.

        The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.

        Specified by:
        headSet in interface SortedSet<E>
        Parameters:
        toElement - high endpoint (exclusive) of the returned set
        Returns:
        a view of the portion of this set whose elements are strictly less than toElement

      • last

        public E last()
        Description copied from interface: java.util.SortedSet
        Returns the last (highest) element currently in this set.
        Specified by:
        last in interface SortedSet<E>
        Returns:
        the last (highest) element currently in this set

      • subSet

        public SortedSet<E> subSet(E fromElement,
                           E toElement)
        Description copied from interface: java.util.SortedSet
        Returns a view of the portion of this set whose elements range from fromElement, inclusive, to toElement, exclusive. (If fromElement and toElement are equal, the returned set is empty.) The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports.

        The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.

        Specified by:
        subSet in interface SortedSet<E>
        Parameters:
        fromElement - low endpoint (inclusive) of the returned set
        toElement - high endpoint (exclusive) of the returned set
        Returns:
        a view of the portion of this set whose elements range from fromElement, inclusive, to toElement, exclusive

      • tailSet

        public SortedSet<E> tailSet(E fromElement)
        Description copied from interface: java.util.SortedSet
        Returns a view of the portion of this set whose elements are greater than or equal to fromElement. The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports.

        The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.

        Specified by:
        tailSet in interface SortedSet<E>
        Parameters:
        fromElement - low endpoint (inclusive) of the returned set
        Returns:
        a view of the portion of this set whose elements are greater than or equal to fromElement