net.cscott.jutil

Class UniqueVector<E>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList<E>

net.cscott.jutil.UniqueVector<E>

All Implemented Interfaces:

java.lang.Cloneable, java.lang.Iterable<E>, java.util.Collection<E>, java.util.List<E>, java.util.Set<E>

Direct Known Subclasses:

UniqueStack

public class UniqueVector<E>
extends java.util.AbstractList<E>
implements java.util.Set<E>, java.lang.Cloneable

A unique vector refuses to addElement duplicates.

Conforms to the JDK 1.2 Collections API.

Version:

$Id: UniqueVector.java,v 1.6 2006-10-30 19:58:07 cananian Exp $

Author:

C. Scott Ananian

See Also:

Vector, Hashtable

Field Summary

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Constructor and Description
UniqueVector() Constructs an empty UniqueVector.
UniqueVector(java.util.Collection<? extends E> c) Constructs a vector containing the elements of the specified Collection, in the order they are returned by the collection's iterator.
UniqueVector(int initialCapacity) Constructs an empty UniqueVector with the specified initial capacity.

Method Summary

Modifier and Type	Method and Description
boolean	add(E obj) Adds the specified component to the end of this vector, increasing its size by one, if it doesn't already exist in the vector.
void	add(int index, E element) Inserts the specified element at the specified position in this list.
void	addElement(E obj) Adds the specified component to the end of this vector, increasing its size by one, if it doesn't already exist in the vector.
int	capacity() Returns the current capacity of this vector.
void	clear() Removes all of the elements from this collection.
UniqueVector<E>	clone() Returns a clone of this vector.
boolean	contains(java.lang.Object elem) Tests if the specified object is a component in this vector.
void	copyInto(java.lang.Object[] anArray) Copies the components of this vector into the specified array.
E	elementAt(int index) Returns the component at the specified index.
java.util.Enumeration<E>	elements() Returns an enumeration of the components of this vector.
void	ensureCapacity(int minCapacity) Increases the capacity of this vector, if necessary, to ensure that it can hold at least the number of components specified by the minimum capacity argument.
boolean	equals(java.lang.Object o)
E	firstElement() Returns the first component of this vector.
E	get(int index) Returns the element at the specified posision in this vector.
int	hashCode()
int	indexOf(java.lang.Object elem) Returns the first (and only) occurrence of the given argument, testing for equality using the equals method.
int	indexOf(java.lang.Object elem, int index) Returns the first occurrence of the given argument, beginning the search at index, and testing for equality using the equals method.
void	insertElementAt(E obj, int index) Inserts the specified object as a component in this vector at the specified index.
boolean	isEmpty() Tests if this vector has no components.
E	lastElement() Returns the last component of the vector.
int	lastIndexOf(java.lang.Object elem) Returns the index of the last (and only) occurrence of the specified object in this vector.
int	lastIndexOf(java.lang.Object elem, int index) Searches backwards for the specified object, starting from the specified index, and returns an index to it.
E	remove(int index) Removes the element at the specified position in this vector.
void	removeAllElements() Removes all components from this vector and sets its size to zero.
boolean	removeElement(java.lang.Object obj) Removes the first (and only) occurance of the argument from this vector.
void	removeElementAt(int index) Deletes the component at the specified index.
E	set(int index, E obj) Replaces the element at the specified position in this vector with the specified element.
void	setElementAt(E obj, int index) Sets the component at the specified index of this vector to be the specified object.
int	size() Returns the number of components in this vector.
java.lang.Object[]	toArray()
<T> T[]	toArray(T[] a)
java.lang.String	toString() Returns a string representation of this vector.
void	trimToSize() Trims the capacity of this vector to be the vector's current size.

Methods inherited from class java.util.AbstractList

addAll, iterator, listIterator, listIterator, removeRange, subList

Methods inherited from class java.util.AbstractCollection

addAll, containsAll, remove, removeAll, retainAll

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Set

addAll, containsAll, iterator, remove, removeAll, retainAll, spliterator

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.List

addAll, containsAll, remove, removeAll, replaceAll, retainAll, sort, spliterator

Constructor Detail

UniqueVector

public UniqueVector()

Constructs an empty UniqueVector.

UniqueVector

public UniqueVector(int initialCapacity)

Constructs an empty UniqueVector with the specified initial capacity.

UniqueVector

public UniqueVector(java.util.Collection<? extends E> c)

Constructs a vector containing the elements of the specified Collection, in the order they are returned by the collection's iterator. Duplicate elements are skipped.

Method Detail

addElement

public void addElement(E obj)

Adds the specified component to the end of this vector, increasing its size by one, if it doesn't already exist in the vector. Duplicate elements are thrown away. The capacity of the vector is increased if necessary.

Parameters:

obj - the component to be added.

add

public void add(int index,
                E element)

Inserts the specified element at the specified position in this list. To maintain uniqueness, any previous instance of this element in the vector is removed prior to insertion.

Specified by:

add in interface java.util.List<E>

Overrides:

add in class java.util.AbstractList<E>

Parameters:

index - the specified position.

element - the element to be inserted.

add

public boolean add(E obj)

Adds the specified component to the end of this vector, increasing its size by one, if it doesn't already exist in the vector. Duplicate elements are thrown away. The capacity of the vector is increased if necessary.

Specified by:

add in interface java.util.Collection<E>

Specified by:

add in interface java.util.List<E>

Specified by:

add in interface java.util.Set<E>

Overrides:

add in class java.util.AbstractList<E>

Parameters:

obj - the component to be added.

capacity

public int capacity()

Returns the current capacity of this vector.

Throws:

java.lang.UnsupportedOperationException - not supported.

clone

public UniqueVector<E> clone()
                      throws java.lang.CloneNotSupportedException

Returns a clone of this vector.

Overrides:

clone in class java.lang.Object

Returns:

a clone of this vector.

Throws:

java.lang.CloneNotSupportedException - if the UniqueVector cannot be cloned.

contains

public boolean contains(java.lang.Object elem)

Tests if the specified object is a component in this vector.

Specified by:

contains in interface java.util.Collection<E>

Specified by:

contains in interface java.util.List<E>

Specified by:

contains in interface java.util.Set<E>

Overrides:

contains in class java.util.AbstractCollection<E>

Parameters:

elem - an object

Returns:

true if the specified object is a component in this vector; false otherwise.

copyInto

public void copyInto(java.lang.Object[] anArray)

Copies the components of this vector into the specified array. The array must be big enough to hold all the objects in this vector.

Parameters:

anArray - the array into which the components get copied.

toArray

public java.lang.Object[] toArray()

Specified by:

toArray in interface java.util.Collection<E>

Specified by:

toArray in interface java.util.List<E>

Specified by:

toArray in interface java.util.Set<E>

Overrides:

toArray in class java.util.AbstractCollection<E>

toArray

public <T> T[] toArray(T[] a)

Specified by:

toArray in interface java.util.Collection<E>

Specified by:

toArray in interface java.util.List<E>

Specified by:

toArray in interface java.util.Set<E>

Overrides:

toArray in class java.util.AbstractCollection<E>

elementAt

public E elementAt(int index)

Returns the component at the specified index.

Parameters:

index - an index into this vector.

Returns:

the component at the specified index.

Throws:

java.lang.ArrayIndexOutOfBoundsException - if an invalid index was given.

get

public E get(int index)

Returns the element at the specified posision in this vector.

Specified by:

get in interface java.util.List<E>

Specified by:

get in class java.util.AbstractList<E>

elements

public java.util.Enumeration<E> elements()

Returns an enumeration of the components of this vector.

Returns:

an enumeration of the components of this vector.

ensureCapacity

public void ensureCapacity(int minCapacity)

Increases the capacity of this vector, if necessary, to ensure that it can hold at least the number of components specified by the minimum capacity argument.

Parameters:

minCapacity - the desired minimum capacity.

firstElement

public E firstElement()

Returns the first component of this vector.

Returns:

the first component of this vector.

Throws:

java.util.NoSuchElementException - if this vector has no components.

indexOf

public int indexOf(java.lang.Object elem)

Returns the first (and only) occurrence of the given argument, testing for equality using the equals method.

Specified by:

indexOf in interface java.util.List<E>

Overrides:

indexOf in class java.util.AbstractList<E>

Parameters:

elem - an object

Returns:

the index of the first occurrence of the argument in this vector; returns -1 if the object is not found.

indexOf

public int indexOf(java.lang.Object elem,
                   int index)

Returns the first occurrence of the given argument, beginning the search at index, and testing for equality using the equals method.

Parameters:

elem - an object.

index - the index to start searching from.

Returns:

the index of the first occurrence of the object argument in this vector at position index or later in the vector; returns -1 if the object is not found.

insertElementAt

public void insertElementAt(E obj,
                            int index)

Inserts the specified object as a component in this vector at the specified index. Each component in this vector with an index greater or equal to the specified index is shifted upward to have an index one greater than the value it had previously.

The index must be a value greater than or equal to 0 and less than or equal to the current size of the vector.

To maintain uniqueness, removed any previous instance of the component in the vector before insertion.

Parameters:

obj - the component to insert.

index - where to insert the new component.

Throws:

java.lang.ArrayIndexOutOfBoundsException - if the index was invalid.

isEmpty

public boolean isEmpty()

Tests if this vector has no components.

Specified by:

isEmpty in interface java.util.Collection<E>

Specified by:

isEmpty in interface java.util.List<E>

Specified by:

isEmpty in interface java.util.Set<E>

Overrides:

isEmpty in class java.util.AbstractCollection<E>

Returns:

true if this vector has no components; false otherwise.

lastElement

public E lastElement()

Returns the last component of the vector.

Returns:

the last component of the vector, i.e., the component at index size()-1.

Throws:

java.util.NoSuchElementException - if this vector is empty.

lastIndexOf

public int lastIndexOf(java.lang.Object elem)

Returns the index of the last (and only) occurrence of the specified object in this vector.

Specified by:

lastIndexOf in interface java.util.List<E>

Overrides:

lastIndexOf in class java.util.AbstractList<E>

Parameters:

elem - the desired component.

Returns:

the index of the last occurrence of the specified object in this vector; returns -1 if the object is not found.

lastIndexOf

public int lastIndexOf(java.lang.Object elem,
                       int index)

Searches backwards for the specified object, starting from the specified index, and returns an index to it.

Parameters:

elem - the desired component.

index - the index to start searching from.

Returns:

the index of the last occurrence of the specified object in this vector at position less than index in the vector; -1 if the object is not found.

removeAllElements

public void removeAllElements()

Removes all components from this vector and sets its size to zero.

clear

public void clear()

Removes all of the elements from this collection.

Specified by:

clear in interface java.util.Collection<E>

Specified by:

clear in interface java.util.List<E>

Specified by:

clear in interface java.util.Set<E>

Overrides:

clear in class java.util.AbstractList<E>

removeElement

public final boolean removeElement(java.lang.Object obj)

Removes the first (and only) occurance of the argument from this vector. If the object is found in this vector, each component in the vector with an index greater or equal to the object's index is shifted downward to have an index one smaller than the value it had previously.

Parameters:

obj - the component to be removed.

Returns:

true if the argument was a component of this vector; false otherwise.

removeElementAt

public void removeElementAt(int index)

Deletes the component at the specified index. Each component in this vector with an index greater than or equal to the specified index is shifted downward to have an index one smaller than the value it had previously.

The index must be a value greater than or equal to 0 and less than the current size of the vector.

Parameters:

index - the index of the object to remove.

Throws:

java.lang.ArrayIndexOutOfBoundsException - if the index was invalid.

remove

public E remove(int index)

Removes the element at the specified position in this vector.

Specified by:

remove in interface java.util.List<E>

Overrides:

remove in class java.util.AbstractList<E>

setElementAt

public void setElementAt(E obj,
                         int index)

Sets the component at the specified index of this vector to be the specified object. The previous component at that position is discarded.

The index must be a value greater than or equal to 0 and less than the current size of the vector.

Nothing is done if the component at index is equal to obj. To maintain uniqueness, any component equal to obj is removed before the setElementAt() is done.

Parameters:

obj - what the component is to be set to.

index - the specified index.

Throws:

java.lang.ArrayIndexOutOfBoundsException - if the index was invalid.

set

public E set(int index,
             E obj)

Replaces the element at the specified position in this vector with the specified element.

Specified by:

set in interface java.util.List<E>

Overrides:

set in class java.util.AbstractList<E>

size

public int size()

Returns the number of components in this vector.

Specified by:

size in interface java.util.Collection<E>

Specified by:

size in interface java.util.List<E>

Specified by:

size in interface java.util.Set<E>

Specified by:

size in class java.util.AbstractCollection<E>

Returns:

the number of components in this vector.

toString

public java.lang.String toString()

Returns a string representation of this vector.

Overrides:

toString in class java.util.AbstractCollection<E>

Returns:

a string representation of this vector.

trimToSize

public void trimToSize()

Trims the capacity of this vector to be the vector's current size. An application can use this operation to minimize the storage of a vector.

hashCode

public int hashCode()

Specified by:

hashCode in interface java.util.Collection<E>

Specified by:

hashCode in interface java.util.List<E>

Specified by:

hashCode in interface java.util.Set<E>

Overrides:

hashCode in class java.util.AbstractList<E>

equals

public boolean equals(java.lang.Object o)

Specified by:

equals in interface java.util.Collection<E>

Specified by:

equals in interface java.util.List<E>

Specified by:

equals in interface java.util.Set<E>

Overrides:

equals in class java.util.AbstractList<E>