org.jutil.java.collections
Class Singleton

java.lang.Object
  |
  +--java.util.AbstractCollection
        |
        +--java.util.AbstractSet
              |
              +--org.jutil.java.collections.Singleton

All Implemented Interfaces:

java.util.Collection, java.util.Set

public final class Singleton

extends java.util.AbstractSet

Version:

$Revision: 1.5 $

Author:

Jan Dockx

Inner Class Summary

class

Singleton.SingletonIterator

Field Summary

static java.lang.String

CVS_REVISION

Constructor Summary

Singleton(java.lang.Object onlyElement)
public behavior

post getOnlyElement() == onlyElement;
Initialize a new Singleton containing the given element.

Method Summary

boolean	add(java.lang.Object o) also public behavior post false; exception UnsupportedOperationException true; See superclass
boolean	addAll(java.util.Collection c) also public behavior post false; exception UnsupportedOperationException true; See superclass
void	clear() also public behavior post false; exception UnsupportedOperationException true; See superclass
boolean	contains(java.lang.Object o) also public behavior post \result == ((getOnlyElement() == null) && (o == null)) || getOnlyElement().equals(o); See superclass
java.lang.Object	getOnlyElement() Return the only element in this Singleton.
boolean	isEmpty() also public behavior post \result == false; See superclass
java.util.Iterator	iterator() also public behavior post \result instanceof SingletonIterator; post \result != null; See superclass
boolean	remove(java.lang.Object o) also public behavior post false; exception UnsupportedOperationException true; See superclass
boolean	removeAll(java.util.Collection c) also public behavior post false; exception UnsupportedOperationException true; See superclass
boolean	retainAll(java.util.Collection c) also public behavior post false; exception UnsupportedOperationException true; See superclass
int	size() also public behavior post \result == 1; See superclass
java.lang.Object[]	toArray() also public behavior post \result.length = 1; post \result[0] == getOnlyElement(); See superclass
java.lang.Object[]	toArray(java.lang.Object[] a) also public behavior post \result.getClass().getComponentType() == a.getClass().getComponentType(); post \result[0] == getOnlyElement(); post (a.length >= 1) ==> (\result == a); post (a.length < 1) ==> (\result.length == 1); exception NullPointerException a == null; exception ArrayStoreException (getOnlyElement() != null) && (! a.getClass().isInstance(getOnlyElement())); See superclass

Methods inherited from class java.util.AbstractSet

equals, hashCode

Methods inherited from class java.util.AbstractCollection

containsAll, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Set

containsAll

Field Detail

CVS_REVISION

public static final java.lang.String CVS_REVISION

Constructor Detail

Singleton

public Singleton(java.lang.Object onlyElement)

public behavior

post getOnlyElement() == onlyElement;
Initialize a new Singleton containing the given element.

Parameters:

onlyElement - The only element of this Singleton.

Method Detail

getOnlyElement

public java.lang.Object getOnlyElement()

Return the only element in this Singleton.

size

public int size()

also public behavior

post \result == 1;
See superclass

Overrides:

size in class java.util.AbstractCollection

isEmpty

public boolean isEmpty()

also public behavior

post \result == false;
See superclass

Overrides:

isEmpty in class java.util.AbstractCollection

contains

public boolean contains(java.lang.Object o)

also public behavior

post \result ==
((getOnlyElement() == null) && (o == null)) ||
getOnlyElement().equals(o);
See superclass

Overrides:

contains in class java.util.AbstractCollection

iterator

public java.util.Iterator iterator()

also public behavior

post \result instanceof SingletonIterator;
post \result != null;
See superclass

Overrides:

iterator in class java.util.AbstractCollection

toArray

public java.lang.Object[] toArray()

also public behavior

post \result.length = 1;
post \result[0] == getOnlyElement();
See superclass

Overrides:

toArray in class java.util.AbstractCollection

toArray

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

also public behavior

post \result.getClass().getComponentType() == a.getClass().getComponentType();
post \result[0] == getOnlyElement();
post (a.length >= 1) ==> (\result == a);
post (a.length < 1) ==> (\result.length == 1);
exception NullPointerException
a == null;
exception ArrayStoreException
(getOnlyElement() != null) &&
(! a.getClass().isInstance(getOnlyElement()));
See superclass

Overrides:

toArray in class java.util.AbstractCollection

add

public boolean add(java.lang.Object o)
            throws java.lang.UnsupportedOperationException

also public behavior

post false;
exception UnsupportedOperationException true;
See superclass

Overrides:

add in class java.util.AbstractCollection

remove

public boolean remove(java.lang.Object o)
               throws java.lang.UnsupportedOperationException

also public behavior

post false;
exception UnsupportedOperationException true;
See superclass

Overrides:

remove in class java.util.AbstractCollection

addAll

public boolean addAll(java.util.Collection c)
               throws java.lang.UnsupportedOperationException

also public behavior

post false;
exception UnsupportedOperationException true;
See superclass

Overrides:

addAll in class java.util.AbstractCollection

retainAll

public boolean retainAll(java.util.Collection c)
                  throws java.lang.UnsupportedOperationException

also public behavior

post false;
exception UnsupportedOperationException true;
See superclass

Overrides:

retainAll in class java.util.AbstractCollection

removeAll

public boolean removeAll(java.util.Collection c)
                  throws java.lang.UnsupportedOperationException

also public behavior

post false;
exception UnsupportedOperationException true;
See superclass

Overrides:

removeAll in class java.util.AbstractSet

clear

public void clear()
           throws java.lang.UnsupportedOperationException

also public behavior

post false;
exception UnsupportedOperationException true;
See superclass

Overrides:

clear in class java.util.AbstractCollection