Package java.util

Class Dictionary<K,​V>

java.lang.Object
java.util.Dictionary<K,​V>
Direct Known Subclasses:
Hashtable
public abstract class Dictionary<K,​V>
extends Object
Note: Do not use this class since it is obsolete. Please use the Map interface for new implementations.

Dictionary is an abstract class which is the superclass of all classes that associate keys with values, such as Hashtable.

Since:
1.0
See Also:
Hashtable

  • Constructor Summary

    Constructors
    Constructor Description
    Dictionary()
    Constructs a new instance of this class.

  • Method Summary

    Modifier and Type Method Description
    abstract Enumeration<V> elements()
    Returns an enumeration on the elements of this dictionary.
    abstract V get​(Object key)
    Returns the value which is associated with key.
    abstract boolean isEmpty()
    Returns true if this dictionary has no key/value pairs.
    abstract Enumeration<K> keys()
    Returns an enumeration on the keys of this dictionary.
    abstract V put​(K key, V value)
    Associate key with value in this dictionary.
    abstract V remove​(Object key)
    Removes the key/value pair with the specified key from this dictionary.
    abstract int size()
    Returns the number of key/value pairs in this dictionary.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Dictionary

      public Dictionary()
      Constructs a new instance of this class.

  • Method Details

    • elements

      public abstract Enumeration<V> elements()
      Returns an enumeration on the elements of this dictionary.
      Returns:
      an enumeration of the values of this dictionary.
      See Also:
      keys(), size(), Enumeration

    • get

      public abstract V get​(Object key)
      Returns the value which is associated with key.
      Parameters:
      key - the key of the value returned.
      Returns:
      the value associated with key, or null if the specified key does not exist.
      See Also:
      put(K, V)

    • isEmpty

      public abstract boolean isEmpty()
      Returns true if this dictionary has no key/value pairs.
      Returns:
      true if this dictionary has no key/value pairs, false otherwise.
      See Also:
      size()

    • keys

      public abstract Enumeration<K> keys()
      Returns an enumeration on the keys of this dictionary.
      Returns:
      an enumeration of the keys of this dictionary.
      See Also:
      elements(), size(), Enumeration

    • put

      public abstract V put​(K key, V value)
      Associate key with value in this dictionary. If key exists in the dictionary before this call, the old value in the dictionary is replaced by value.
      Parameters:
      key - the key to add.
      value - the value to add.
      Returns:
      the old value previously associated with key or null if key is new to the dictionary.
      See Also:
      elements(), get(java.lang.Object), keys()

    • remove

      public abstract V remove​(Object key)
      Removes the key/value pair with the specified key from this dictionary.
      Parameters:
      key - the key to remove.
      Returns:
      the associated value before the deletion or null if key was not known to this dictionary.
      See Also:
      get(java.lang.Object), put(K, V)

    • size

      public abstract int size()
      Returns the number of key/value pairs in this dictionary.
      Returns:
      the number of key/value pairs in this dictionary.
      See Also:
      elements(), keys()