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Note: Do not use this class since it is obsolete.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 Object

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

Modifier and Type	Method	Description
protected Object	clone()
boolean	equals(Object obj)	Indicates whether some other object is "equal to" this one.
final Class	getClass()	Returns the runtime class of an object.
int	hashCode()	Returns a hash code value for the object.
final void	notify()	Wakes up a single thread that is waiting on this object's monitor.
final void	notifyAll()	Wakes up all threads that are waiting on this object's monitor.
String	toString()	Returns a string representation of the object.
final void	wait()	Causes current thread to wait until another thread invokes the method or the method for this object.
final void	wait(long timeout)	Causes current thread to wait until either another thread invokes the method or the method for this object, or a specified amount of time has elapsed.
final void	wait(long timeout, int nanos)	Causes current thread to wait until another thread invokes the method or the method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.

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(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(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()