com.sibvisions.util
Class GroupHashtable<G,K,V>

java.lang.Object
  com.sibvisions.util.GroupHashtable<G,K,V>

Type Parameters:

G - group class

K - key class

V - value class

public class GroupHashtable<G,K,V>
extends Object

The GroupHashtable is a utility class to group multiple key/value pairs with a single group key.
Its implementation has a Hashtable, for the group, which contains multiple Hashtables, for the key/value pairs.

Constructor Summary

GroupHashtable()

Method Summary

void	clear() Clears all entries.
void	clear(G pGroup) Clears all entries from a specific group.
boolean	constainsKey(G pGroup, K pKey) Tests if the specified object is a key in the group mapping.
boolean	containsValue(G pGroup, V pValue) Returns true if the group maps one or more keys to this value.
Enumeration<V>	elements(G pGroup) Returns an enumeration of the values associated with a group, in this hashtable.
Hashtable<K,V>	get(G pGroup) Returns the internal Hashtable associated with the pGroup.
V	get(G pGroup, K pKey) Returns the value to which the specified key is mapped.
Enumeration<K>	keys(G pGroup) Returns an enumeration of the keys associated with a group, in this hashtable.
void	put(G pGroup, K pKey, V pValue) Associates the specified value with the specified key to the group.
boolean	remove(G pGroup) Removes the mapping of an entire group if it is present.
V	remove(G pGroup, K pKey) Removes the mapping for a key from its group if it is present.
int	size() Returns the group count.
int	size(G pGroup) Returns the number of group elements.

Methods inherited from class java.lang.Object

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

Constructor Detail

GroupHashtable

public GroupHashtable()

Method Detail

put

public void put(G pGroup,
                K pKey,
                V pValue)

Associates the specified value with the specified key to the group.

Parameters:

pGroup - group identifier

pKey - key with which the specified value is to be associated

pValue - value to be associated with the specified key

get

public V get(G pGroup,
             K pKey)

Returns the value to which the specified key is mapped.

Parameters:

pGroup - group identifier

pKey - the key whose associated value is to be returned

Returns:

the value to which the specified key is mapped or null if the key or the group is not mapped.

get

public Hashtable<K,V> get(G pGroup)

Returns the internal Hashtable associated with the pGroup.

Parameters:

pGroup - group identifier

Returns:

the Hashtable which is mapped to the specified group or null if the pGroup is not mapped

remove

public boolean remove(G pGroup)

Removes the mapping of an entire group if it is present.

Parameters:

pGroup - group identifier

Returns:

true if the group was removed, false if the group is not present or can not be removed

remove

public V remove(G pGroup,
                K pKey)

Removes the mapping for a key from its group if it is present.

Parameters:

pGroup - group identifier

pKey - key to remove

Returns:

the previous value associated with the key or null if there is no mapping the key

size

public int size()

Returns the group count.

Returns:

number of groups

size

public int size(G pGroup)

Returns the number of group elements.

Parameters:

pGroup - group identifier

Returns:

number of group elements

elements

public Enumeration<V> elements(G pGroup)

Returns an enumeration of the values associated with a group, in this hashtable. Use the Enumeration methods on the returned object to fetch the elements sequentially.

Parameters:

pGroup - group identifier

Returns:

an enumeration of the values in this hashtable

keys

public Enumeration<K> keys(G pGroup)

Returns an enumeration of the keys associated with a group, in this hashtable.

Parameters:

pGroup - group identifier

Returns:

enumeration of the keys in this hashtable

containsValue

public boolean containsValue(G pGroup,
                             V pValue)

Returns true if the group maps one or more keys to this value.

Parameters:

pGroup - group identifier

pValue - value whose presence is to be tested

Returns:

true if the group maps one or more keys to the specified value, false otherwise

constainsKey

public boolean constainsKey(G pGroup,
                            K pKey)

Tests if the specified object is a key in the group mapping.

Parameters:

pGroup - group identifier

pKey - possible key

Returns:

true if and only if the specified key is mapped in the group, false otherwise

clear

public void clear()

Clears all entries.

clear

public void clear(G pGroup)

Clears all entries from a specific group.

Parameters:

pGroup - the group identifier