ariba.util.core
Class DynamicArray

java.lang.Object
  ariba.util.core.DynamicArray

Direct Known Subclasses:

BooleanArray, FileArray, IntegerArray, MapArray, ObjectArray, StringArray

public abstract class DynamicArray
extends Object

A DynamicArray is like List except that is exposes the underlying array. DynamicArray is abstract so that clients can supply a method to allocate the array to be of a particular type. This gets back some of the runtime type checking that List loses, and allows more concise enumeration. Here is a sample concrete subclass:

        public class IntegerArray extends DynamicArray
        {
            public Object[] alloc (int size)
            {
                return new Integer[ size ];
            }

            public final Integer[] array ()
            {
                return (Integer[]) array;
            }
        }
    

A use of IntegerArray might look like this:

        IntegerArray v = Util.integerList();
        v.addElement (Constants.getInteger(1));
        v.addElement (Constants.getInteger(2));

        Integer[] a = v.array();
        for (int k = 0; k < v.inUse; k++) {
            doIntegerOp(a[k]);
        }
    

Using List, each element access in the loop would entail a procedure call and a cast.

Note that this is not a thread-safe implementation. Consumer is responsible for synchronizing the access to the object

Field Summary

Object[]	array The storage array.
int	inUse Deprecated. see inUse()

Constructor Summary

DynamicArray()
Create a DynamicArray with a default storage size.

DynamicArray(int size)
Create a new DynamicArray

Method Summary

void	add(int index, Object element) Insert an object into the array
void	add(Object o) Add an element to the array.
void	addAll(Collection c) Add all the elements of the specified Collection.
void	addAll(DynamicArray that) Add all the elements from another array.
void	addAll(Object[] that) Add all the elements from another array.
void	addElement(Object o) Deprecated. use add instead
void	addElementIfAbsent(Object o) Add an element to the array, if it isn't in the array
void	addElements(DynamicArray that) Add all the elements from another array.
void	addElements(Object[] that) Add all the elements from another array.
void	addIdentical(Object o) Add an element to the array, if it isn't in the array
abstract Object[]	alloc(int size) Allocate the storage array.
Object[]	arrayCopy() Return a copy of the underlying array sized to fit the number of allocated elements.
void	clear() Resets the array The size of underlying array remains the same
boolean	contains(Object x) Check if the array contains an object.
boolean	containsIdentical(Object x) Check if the array contains an object.
Object[]	extend(Object[] a, Object x) A version of addElement for cases where all you've got is a Foo[]
int	indexOf(Object o) Find the location of an object in the array.
void	insertElementAt(Object element, int index) Insert an object into the array
int	inUse() The number of members that are currently used.
void	makeRoomFor(int want) Make sure there is room for additional elements.
Object	remove(int index) Remove an element from the array
Object	removeElementAt(int index) Remove an element from the array
void	setArray(Object[] array) Replace the storage array.
void	setCapacity(int size) Change the size of the storage.
List	toList() Converts the array to a List.
String	toString() Converts to a String.
Object[]	trim() Make the allocated length equal the number of elements in use.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

array

public Object[] array

The storage array. This member should be accessed directly for reading only It is public for unit tests only.

inUse

public int inUse

Deprecated. see inUse()

The number of members that are currently used. This is the logical length of the array. This member should be accessed directly only for reading.

Constructor Detail

DynamicArray

public DynamicArray()

Create a DynamicArray with a default storage size.

DynamicArray

public DynamicArray(int size)

Create a new DynamicArray

Parameters:

size - The starting size of the storage array. A size of -1 creates an instance with no array allocated.

Method Detail

inUse

public int inUse()

The number of members that are currently used. This is the logical length of the array. This member should be accessed directly only for reading.

Returns:

the number of members that are currently used

setArray

public void setArray(Object[] array)

Replace the storage array. The new storage array has to be the right type or the next call to array() will cause a ClassCastException. Must override in subclass if using the local array hack to get around the Netscape varifier bug involving casting of Object arrays.

Parameters:

array - The new array to use as storage

setCapacity

public void setCapacity(int size)

Change the size of the storage. The size cannot be decreased below the number of elements that are currently being used.

Parameters:

size - The new requested size

makeRoomFor

public void makeRoomFor(int want)

Make sure there is room for additional elements.

Parameters:

want - The number of elements we want to have space for

addElement

public void addElement(Object o)

Deprecated. use add instead

Add an element to the array.

Parameters:

o - The element to add

See Also:

add(Object)

add

public void add(Object o)

Add an element to the array.

Parameters:

o - The element to add

addElementIfAbsent

public void addElementIfAbsent(Object o)

Add an element to the array, if it isn't in the array

Parameters:

o - The element to add. If o is already in the array then it is not added. o.equals() is used to compare elements.

addIdentical

public void addIdentical(Object o)

Add an element to the array, if it isn't in the array

Parameters:

o - The element to add. If o is already in the array then it is not added. The == operator is used to compare elements.

addElements

public void addElements(DynamicArray that)

Add all the elements from another array.

Parameters:

that - The array that we will copy from

addAll

public void addAll(DynamicArray that)

Add all the elements from another array.

Parameters:

that - The array that we will copy from

addAll

public void addAll(Collection c)

Add all the elements of the specified Collection.

Parameters:

c - The Collection that we will copy from

addElements

public void addElements(Object[] that)

Add all the elements from another array.

Parameters:

that - The array that we will copy from

addAll

public void addAll(Object[] that)

Add all the elements from another array.

Parameters:

that - The array that we will copy from

containsIdentical

public boolean containsIdentical(Object x)

Check if the array contains an object. The == operator is used to compare objects

Parameters:

x - the object to check for

Returns:

true if the object is in the array

contains

public boolean contains(Object x)

Check if the array contains an object. Object.equals() is used to compare objects.

Parameters:

x - the object to check for

Returns:

true if the object is in the array

indexOf

public int indexOf(Object o)

Find the location of an object in the array. Object.equals() is used to compare objects.

Parameters:

o - The object to look for

Returns:

the index of the object, or -1 if it is not found

arrayCopy

public Object[] arrayCopy()

Return a copy of the underlying array sized to fit the number of allocated elements.

Returns:

The array copy

trim

public Object[] trim()

Make the allocated length equal the number of elements in use.

Returns:

the trimmed array.

removeElementAt

public Object removeElementAt(int index)

Remove an element from the array

Parameters:

index - The index of the element to remove

Returns:

the removed object

Throws:

ArrayIndexOutOfBoundsException - when index is larger than the logical size of the array (inUse) or when it is less than 0.

remove

public Object remove(int index)

Remove an element from the array

Parameters:

index - The index of the element to remove

Returns:

the removed object

Throws:

ArrayIndexOutOfBoundsException - when index is larger than the logical size of the array (inUse) or when it is less than 0.

insertElementAt

public void insertElementAt(Object element,
                            int index)

Insert an object into the array

Parameters:

element - The object to be inserted

index - The location where the object should be inserted

Throws:

ArrayIndexOutOfBoundsException - when index is larger than the logical size of the array (inUse)

add

public void add(int index,
                Object element)

Insert an object into the array

Parameters:

element - The object to be inserted

index - The location where the object should be inserted

Throws:

ArrayIndexOutOfBoundsException - when index is larger than the logical size of the array (inUse)

alloc

public abstract Object[] alloc(int size)

Allocate the storage array. Subclasses should override this, allocating an array of the correct type.

Parameters:

size - The size of the array to allocate

Returns:

The allocated array

extend

public Object[] extend(Object[] a,
                       Object x)

A version of addElement for cases where all you've got is a Foo[]

Parameters:

a - original array

x - element to add

Returns:

new array of length a.length+1 containing contents of a plus x as the last element

toString

public String toString()

Converts to a String. toString() is called on each element individually and then a space is placed between each element. The entire array is enclosed in parentheses

Overrides:

toString in class Object

Returns:

the String representation of the Dynamic array

toList

public List toList()

Converts the array to a List.

Returns:

A List version of the array

clear

public void clear()

Resets the array The size of underlying array remains the same