java.util

Class Dictionary<K,V>

java.lang.Object

java.util.Dictionary<K,V>

Type Parameters:

K - Type used with Keys

V - Type used with Values

Direct Known Subclasses:

Hashtable

public abstract class Dictionary<K,V>
extends Object

The Dictionary class is the abstract parent of any class, such as Hashtable, which maps keys to values.

Constructor Summary

Constructors

Constructor and Description
Dictionary() Sole Constructor.

Method Summary

Modifier and Type	Method and Description
abstract Enumeration<V>	elements() Returns an enumeration of the values in this dictionary.
abstract V	get(K key) Returns the value to which the key is mapped in this dictionary.
abstract boolean	isEmpty() Tests if this dictionary maps no keys to value.
abstract Enumeration<K>	keys() Returns an enumeration of the keys in this dictionary.
abstract V	put(K key, V value) Maps the specified key to the specified value in this dictionary.
abstract V	remove(K key) Removes the key (and its corresponding value) from this dictionary.
abstract int	size() Returns the number of entries (distinct keys) in this dictionary.

Methods inherited from class java.lang.Object

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

Constructor Detail

Dictionary

public Dictionary()

Sole Constructor.

Method Detail

elements

public abstract Enumeration<V> elements()

Returns an enumeration of the values in this dictionary.

Returns:

an enumeration of the values in this dictionary.

get

public abstract V get(K key)

Returns the value to which the key is mapped in this dictionary.

Parameters:

key - a key in this dictionary.

Returns:

the value to which the key is mapped in this dictionary;

isEmpty

public abstract boolean isEmpty()

Tests if this dictionary maps no keys to value.

Returns:

true if this dictionary maps no keys to values; false otherwise.

keys

public abstract Enumeration<K> keys()

Returns an enumeration of the keys in this dictionary.

Returns:

an enumeration of the keys in this dictionary.

put

public abstract V put(K key,
                      V value)

Maps the specified key to the specified value in this dictionary.

Parameters:

key - the hashtable key.

value - the value.

Returns:

the previous value to which the key was mapped in this dictionary, or null if the key did not have a previous mapping.

remove

public abstract V remove(K key)

Removes the key (and its corresponding value) from this dictionary.

Parameters:

key - the key that needs to be removed.

Returns:

the value to which the key had been mapped in this dictionary, or null if the key did not have a mapping.

size

public abstract int size()

Returns the number of entries (distinct keys) in this dictionary.

Returns:

the number of keys in this dictionary.