org.apache.turbine.util
Class SequencedHashtable

java.lang.Object
  java.util.Dictionary
      java.util.Hashtable
          org.apache.turbine.util.SequencedHashtable

All Implemented Interfaces:

java.lang.Cloneable, java.util.Map, java.io.Serializable

Deprecated. Use SequencedHashMap from the commons collections.

public class SequencedHashtable

extends java.util.Hashtable

A Hashtable whose keys are sequenced. The sequencing of the keys allow easy access to the values in the order which they were added in. This class is thread safe.

Implementing the List interface is not possible due to a instance method name clash between the Collection and the List interface:

Collections	boolean remove(Object o)
Lists	Object remove(Object o)

So one cannot implement both interfaces at the same, which is unfortunate because the List interface would be very nice in conjuction with Velocity.

A slightly more complex implementation and interface could involve the use of a list of Map.Entry objects.

Version:

$Id: SequencedHashtable.java 264152 2005-08-29 14:50:22Z henning $

Author:

Daniel Rall

See Also:

Serialized Form

Constructor Summary

SequencedHashtable()
Deprecated. Creates a new instance with default storage.

SequencedHashtable(int size)
Deprecated. Creates a new instance with the specified storage.

Method Summary

void	clear() Deprecated. Clears all elements.
java.lang.Object	clone() Deprecated. Creates a shallow copy of this object, preserving the internal structure by copying only references.
protected void	freshenSequence(java.lang.Object key, java.lang.Object value) Deprecated. Freshens the sequence of the element value if value is not null.
java.lang.Object	get(int index) Deprecated. Returns the key at the specified index.
java.lang.Object	getValue(int index) Deprecated. Returns the value at the specified index.
int	indexOf(java.lang.Object key) Deprecated. Returns the index of the specified key.
java.util.Iterator	iterator() Deprecated. Returns a key iterator.
int	lastIndexOf(java.lang.Object key) Deprecated. Returns the last index of the specified key.
java.lang.Object	put(java.lang.Object key, java.lang.Object value) Deprecated. Stores the provided key/value pair.
void	putAll(java.util.Map t) Deprecated. Stores the provided key/value pairs.
java.lang.Object	remove(int index) Deprecated. Removes the element at the specified index.
java.lang.Object	remove(java.lang.Object key) Deprecated. Removes the element with the specified key.
java.util.List	sequence() Deprecated. Returns the ordered sequence of keys.
java.util.Collection	values() Deprecated. Slightly cheaper implementation of values() method.

Methods inherited from class java.util.Hashtable

contains, containsKey, containsValue, elements, entrySet, equals, get, hashCode, isEmpty, keys, keySet, rehash, size, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

SequencedHashtable

public SequencedHashtable()

Deprecated.

Creates a new instance with default storage.

SequencedHashtable

public SequencedHashtable(int size)

Deprecated.

Creates a new instance with the specified storage.

Parameters:

size - The storage to allocate up front.

Method Detail

clear

public void clear()

Deprecated.

Clears all elements.

clone

public java.lang.Object clone()

Deprecated.

Creates a shallow copy of this object, preserving the internal structure by copying only references. The keys, values, and sequence are not clone()'d.

Returns:

A clone of this instance.

get

public java.lang.Object get(int index)

Deprecated.

Returns the key at the specified index.

getValue

public java.lang.Object getValue(int index)

Deprecated.

Returns the value at the specified index.

indexOf

public int indexOf(java.lang.Object key)

Deprecated.

Returns the index of the specified key.

iterator

public java.util.Iterator iterator()

Deprecated.

Returns a key iterator.

lastIndexOf

public int lastIndexOf(java.lang.Object key)

Deprecated.

Returns the last index of the specified key.

sequence

public java.util.List sequence()

Deprecated.

Returns the ordered sequence of keys. This method is meant to be used for retrieval of Key / Value pairs in e.g. Velocity:

 ## $table contains a sequenced hashtable
 #foreach ($key in $table.sequence())
 <TR>
 <TD>Key: $key</TD>
 </TD>Value: $table.get($key)</TD>
 </TR>
 #end
 

Returns:

The ordered list of keys.

put

public java.lang.Object put(java.lang.Object key,
                            java.lang.Object value)

Deprecated.

Stores the provided key/value pair. Freshens the sequence of existing elements.

Parameters:

key - The key to the provided value.

value - The value to store.

Returns:

The previous value for the specified key, or null if none.

freshenSequence

protected void freshenSequence(java.lang.Object key,
                               java.lang.Object value)

Deprecated.

Freshens the sequence of the element value if value is not null.

Parameters:

key - The key whose sequence to freshen.

value - The value whose existance to check before removing the old key sequence.

putAll

public void putAll(java.util.Map t)

Deprecated.

Stores the provided key/value pairs.

Parameters:

t - The key/value pairs to store.

remove

public java.lang.Object remove(int index)

Deprecated.

Removes the element at the specified index.

Parameters:

index - The index of the object to remove.

Returns:

The previous value coressponding the key, or null if none existed.

remove

public java.lang.Object remove(java.lang.Object key)

Deprecated.

Removes the element with the specified key.

Parameters:

key - The Map key of the object to remove.

Returns:

The previous value coressponding the key, or null if none existed.

values

public java.util.Collection values()

Deprecated.

Slightly cheaper implementation of values() method.