Package java.util

Interface SortedMap<K,​V>

All Superinterfaces:
Map<K,​V>
All Known Subinterfaces:
ConcurrentNavigableMap<K,​V>, NavigableMap<K,​V>
All Known Implementing Classes:
ConcurrentSkipListMap, TreeMap
public interface SortedMap<K,​V>
extends Map<K,​V>
A map that has its keys ordered. The sorting is according to either the natural ordering of its keys or the ordering given by a specified comparator.

  • Nested Class Summary

    Nested classes/interfaces inherited from interface java.util.Map

    Map.Entry<K,​V>

  • Method Summary

    Modifier and Type Method Description
    Comparator<? super K> comparator()
    Returns the comparator used to compare keys in this sorted map, or null if the natural ordering is in use.
    K firstKey()
    Returns the least key in this sorted map.
    SortedMap<K,​V> headMap​(K endKey)
    Returns a sorted map over a range of this sorted map with all keys that are less than the specified endKey.
    K lastKey()
    Returns the greatest key in this sorted map.
    SortedMap<K,​V> subMap​(K startKey, K endKey)
    Returns a sorted map over a range of this sorted map with all keys greater than or equal to the specified startKey and less than the specified endKey.
    SortedMap<K,​V> tailMap​(K startKey)
    Returns a sorted map over a range of this sorted map with all keys that are greater than or equal to the specified startKey.

    Methods inherited from interface java.util.Map

    clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, values

  • Method Details

    • comparator

      Comparator<? super K> comparator()
      Returns the comparator used to compare keys in this sorted map, or null if the natural ordering is in use.

    • firstKey

      K firstKey()
      Returns the least key in this sorted map.
      Throws:
      NoSuchElementException - if this sorted map is empty.

    • headMap

      SortedMap<K,​V> headMap​(K endKey)
      Returns a sorted map over a range of this sorted map with all keys that are less than the specified endKey. Changes to the returned sorted map are reflected in this sorted map and vice versa.

      Note: The returned map will not allow an insertion of a key outside the specified range.

      Parameters:
      endKey - the high boundary of the range specified.
      Returns:
      a sorted map where the keys are less than endKey.
      Throws:
      ClassCastException - if the class of the end key is inappropriate for this sorted map.
      NullPointerException - if the end key is null and this sorted map does not support null keys.
      IllegalArgumentException - if this map is itself a sorted map over a range of another map and the specified key is outside of its range.

    • lastKey

      K lastKey()
      Returns the greatest key in this sorted map.
      Throws:
      NoSuchElementException - if this sorted map is empty.

    • subMap

      SortedMap<K,​V> subMap​(K startKey, K endKey)
      Returns a sorted map over a range of this sorted map with all keys greater than or equal to the specified startKey and less than the specified endKey. Changes to the returned sorted map are reflected in this sorted map and vice versa.

      Note: The returned map will not allow an insertion of a key outside the specified range.

      Parameters:
      startKey - the low boundary of the range (inclusive).
      endKey - the high boundary of the range (exclusive),
      Returns:
      a sorted map with the key from the specified range.
      Throws:
      ClassCastException - if the class of the start or end key is inappropriate for this sorted map.
      NullPointerException - if the start or end key is null and this sorted map does not support null keys.
      IllegalArgumentException - if the start key is greater than the end key, or if this map is itself a sorted map over a range of another sorted map and the specified range is outside of its range.

    • tailMap

      SortedMap<K,​V> tailMap​(K startKey)
      Returns a sorted map over a range of this sorted map with all keys that are greater than or equal to the specified startKey. Changes to the returned sorted map are reflected in this sorted map and vice versa.

      Note: The returned map will not allow an insertion of a key outside the specified range.

      Parameters:
      startKey - the low boundary of the range specified.
      Returns:
      a sorted map where the keys are greater or equal to startKey.
      Throws:
      ClassCastException - if the class of the start key is inappropriate for this sorted map.
      NullPointerException - if the start key is null and this sorted map does not support null keys.
      IllegalArgumentException - if this map itself a sorted map over a range of another map and the specified key is outside of its range.