Package com.google.common.collect

Class ForwardingSortedMap<K,V>

  • All Implemented Interfaces:
    Map<K,V>, SortedMap<K,V>
    Direct Known Subclasses:
    ForwardingNavigableMap
    @GwtCompatible
public abstract class ForwardingSortedMap<K,V>
extends ForwardingMap<K,V>
implements SortedMap<K,V>
    A sorted map which forwards all its method calls to another sorted map. Subclasses should override one or more methods to modify the behavior of the backing sorted map as desired per the decorator pattern.

    Warning: The methods of ForwardingSortedMap forward indiscriminately to the methods of the delegate. For example, overriding ForwardingMap.put(K, V) alone will not change the behavior of ForwardingMap.putAll(java.util.Map<? extends K, ? extends V>), which can lead to unexpected behavior. In this case, you should override putAll as well, either providing your own implementation, or delegating to the provided standardPutAll 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 ForwardingSortedMap.

    Each of the standard methods, where appropriate, use the comparator of the map to test equality for both keys and values, unlike ForwardingMap.

    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 SortedMap<K,V> 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 ForwardingMap<K,V>

      • comparator

        public Comparator<? super K> comparator()
        Description copied from interface: java.util.SortedMap
        Returns the comparator used to order the keys in this map, or null if this map uses the natural ordering of its keys.
        Specified by:
        comparator in interface SortedMap<K,V>
        Returns:
        the comparator used to order the keys in this map, or null if this map uses the natural ordering of its keys

      • firstKey

        public K firstKey()
        Description copied from interface: java.util.SortedMap
        Returns the first (lowest) key currently in this map.
        Specified by:
        firstKey in interface SortedMap<K,V>
        Returns:
        the first (lowest) key currently in this map

      • headMap

        public SortedMap<K,V> headMap(K toKey)
        Description copied from interface: java.util.SortedMap
        Returns a view of the portion of this map whose keys are strictly less than toKey. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.

        The returned map will throw an IllegalArgumentException on an attempt to insert a key outside its range.

        Specified by:
        headMap in interface SortedMap<K,V>
        Parameters:
        toKey - high endpoint (exclusive) of the keys in the returned map
        Returns:
        a view of the portion of this map whose keys are strictly less than toKey

      • lastKey

        public K lastKey()
        Description copied from interface: java.util.SortedMap
        Returns the last (highest) key currently in this map.
        Specified by:
        lastKey in interface SortedMap<K,V>
        Returns:
        the last (highest) key currently in this map

      • subMap

        public SortedMap<K,V> subMap(K fromKey,
                                   K toKey)
        Description copied from interface: java.util.SortedMap
        Returns a view of the portion of this map whose keys range from fromKey, inclusive, to toKey, exclusive. (If fromKey and toKey are equal, the returned map is empty.) The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.

        The returned map will throw an IllegalArgumentException on an attempt to insert a key outside its range.

        Specified by:
        subMap in interface SortedMap<K,V>
        Parameters:
        fromKey - low endpoint (inclusive) of the keys in the returned map
        toKey - high endpoint (exclusive) of the keys in the returned map
        Returns:
        a view of the portion of this map whose keys range from fromKey, inclusive, to toKey, exclusive

      • tailMap

        public SortedMap<K,V> tailMap(K fromKey)
        Description copied from interface: java.util.SortedMap
        Returns a view of the portion of this map whose keys are greater than or equal to fromKey. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.

        The returned map will throw an IllegalArgumentException on an attempt to insert a key outside its range.

        Specified by:
        tailMap in interface SortedMap<K,V>
        Parameters:
        fromKey - low endpoint (inclusive) of the keys in the returned map
        Returns:
        a view of the portion of this map whose keys are greater than or equal to fromKey