net.sf.morph.util
Class ListOrderedSet

java.lang.Object
  net.sf.morph.util.ListOrderedSet

All Implemented Interfaces:

java.lang.Iterable, java.util.Collection, java.util.Set

public class ListOrderedSet
extends java.lang.Object
implements java.util.Set

Decorates another Set to ensure that the order of addition is retained and used by the iterator.

If an object is added to the set for a second time, it will remain in the original position in the iteration. The order can be observed from the set via the iterator or toArray methods.

The ListOrderedSet also has various useful direct methods. These include many from List, such as get(int), remove(int) and indexOf(int). An unmodifiable List view of the set can be obtained via asList().

This class cannot implement the List interface directly as various interface methods (notably equals/hashCode) are incompatable with a set.

This class is Serializable from Commons Collections 3.1.

Note: this class was copied from Commons Collections.

Since:

Commons Collections 3.0

Version:

$Revision: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $

Author:

Stephen Colebourne, Henning P. Schmiedehausen

Field Summary

protected java.util.Collection	collection The collection being decorated
protected java.util.List	setOrder Internal list to hold the sequence of objects

Constructor Summary

	ListOrderedSet() Constructs a new empty ListOrderedSet using a HashSet and an ArrayList internally.
protected	ListOrderedSet(java.util.Set set) Constructor that wraps (not copies).
protected	ListOrderedSet(java.util.Set set, java.util.List list) Constructor that wraps (not copies) the Set and specifies the list to use.

Method Summary

void	add(int index, java.lang.Object object)
boolean	add(java.lang.Object object)
boolean	addAll(java.util.Collection coll)
boolean	addAll(int index, java.util.Collection coll)
java.util.List	asList() Gets an unmodifiable view of the order of the Set.
void	clear()
boolean	contains(java.lang.Object o)
boolean	containsAll(java.util.Collection c)
static ListOrderedSet	decorate(java.util.List list) Factory method to create an ordered set using the supplied list to retain order.
static ListOrderedSet	decorate(java.util.Set set) Factory method to create an ordered set.
static ListOrderedSet	decorate(java.util.Set set, java.util.List list) Factory method to create an ordered set specifying the list and set to use.
java.lang.Object	get(int index)
int	indexOf(java.lang.Object object)
boolean	isEmpty()
java.util.Iterator	iterator()
java.lang.Object	remove(int index)
boolean	remove(java.lang.Object object)
boolean	removeAll(java.util.Collection coll)
boolean	retainAll(java.util.Collection coll)
int	size()
java.lang.Object[]	toArray()
java.lang.Object[]	toArray(java.lang.Object[] a)
java.lang.String	toString() Uses the underlying List's toString so that order is achieved.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Set

equals, hashCode

Field Detail

collection

protected java.util.Collection collection

The collection being decorated

setOrder

protected final java.util.List setOrder

Internal list to hold the sequence of objects

Constructor Detail

ListOrderedSet

public ListOrderedSet()

Constructs a new empty ListOrderedSet using a HashSet and an ArrayList internally.

Since:

Commons Collections 3.1

ListOrderedSet

protected ListOrderedSet(java.util.Set set)

Constructor that wraps (not copies).

Parameters:

set - the set to decorate, must not be null

Throws:

java.lang.IllegalArgumentException - if set is null

ListOrderedSet

protected ListOrderedSet(java.util.Set set,
                         java.util.List list)

Constructor that wraps (not copies) the Set and specifies the list to use.

The set and list must both be correctly initialised to the same elements.

Parameters:

set - the set to decorate, must not be null

list - the list to decorate, must not be null

Throws:

java.lang.IllegalArgumentException - if set or list is null

Method Detail

decorate

public static ListOrderedSet decorate(java.util.Set set,
                                      java.util.List list)

Factory method to create an ordered set specifying the list and set to use.

The list and set must both be empty.

Parameters:

set - the set to decorate, must be empty and not null

list - the list to decorate, must be empty and not null

Throws:

java.lang.IllegalArgumentException - if set or list is null

java.lang.IllegalArgumentException - if either the set or list is not empty

Since:

Commons Collections 3.1

decorate

public static ListOrderedSet decorate(java.util.Set set)

Factory method to create an ordered set.

An ArrayList is used to retain order.

Parameters:

set - the set to decorate, must not be null

Throws:

java.lang.IllegalArgumentException - if set is null

decorate

public static ListOrderedSet decorate(java.util.List list)

Factory method to create an ordered set using the supplied list to retain order.

A HashSet is used for the set behaviour.

NOTE: If the list contains duplicates, the duplicates are removed, altering the specified list.

Parameters:

list - the list to decorate, must not be null

Throws:

java.lang.IllegalArgumentException - if list is null

asList

public java.util.List asList()

Gets an unmodifiable view of the order of the Set.

Returns:

an unmodifiable list view

clear

public void clear()

Specified by:

clear in interface java.util.Collection

Specified by:

clear in interface java.util.Set

iterator

public java.util.Iterator iterator()

Specified by:

iterator in interface java.lang.Iterable

Specified by:

iterator in interface java.util.Collection

Specified by:

iterator in interface java.util.Set

add

public boolean add(java.lang.Object object)

Specified by:

add in interface java.util.Collection

Specified by:

add in interface java.util.Set

addAll

public boolean addAll(java.util.Collection coll)

Specified by:

addAll in interface java.util.Collection

Specified by:

addAll in interface java.util.Set

remove

public boolean remove(java.lang.Object object)

Specified by:

remove in interface java.util.Collection

Specified by:

remove in interface java.util.Set

removeAll

public boolean removeAll(java.util.Collection coll)

Specified by:

removeAll in interface java.util.Collection

Specified by:

removeAll in interface java.util.Set

retainAll

public boolean retainAll(java.util.Collection coll)

Specified by:

retainAll in interface java.util.Collection

Specified by:

retainAll in interface java.util.Set

toArray

public java.lang.Object[] toArray()

Specified by:

toArray in interface java.util.Collection

Specified by:

toArray in interface java.util.Set

toArray

public java.lang.Object[] toArray(java.lang.Object[] a)

Specified by:

toArray in interface java.util.Collection

Specified by:

toArray in interface java.util.Set

get

public java.lang.Object get(int index)

indexOf

public int indexOf(java.lang.Object object)

add

public void add(int index,
                java.lang.Object object)

addAll

public boolean addAll(int index,
                      java.util.Collection coll)

remove

public java.lang.Object remove(int index)

toString

public java.lang.String toString()

Uses the underlying List's toString so that order is achieved. This means that the decorated Set's toString is not used, so any custom toStrings will be ignored.

Overrides:

toString in class java.lang.Object

contains

public boolean contains(java.lang.Object o)

Specified by:

contains in interface java.util.Collection

Specified by:

contains in interface java.util.Set

containsAll

public boolean containsAll(java.util.Collection c)

Specified by:

containsAll in interface java.util.Collection

Specified by:

containsAll in interface java.util.Set

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Collection

Specified by:

isEmpty in interface java.util.Set

size

public int size()

Specified by:

size in interface java.util.Collection

Specified by:

size in interface java.util.Set