org.joshvm.util

Class ArrayList

java.lang.Object

org.joshvm.util.ArrayList

Type Parameters:

K - when you use the enough-polish-client-java5.jar you can parameterize the ArrayList, e.g. ArrayList<Integer> = new ArrayList<Integer>(10);

public class ArrayList
extends Object

Provides an flexible list for storing objects.

This ArrayList is mostly compatible with the java.util.ArrayList of the J2SE. It lacks, however, some not often used methods. Also some methods like add or remove do not return a boolean value, since true is always returned (or an exception is thrown) anyhow. This way we can save some precious space!

Workarounds for some of the missing methods:

• isEmpty() Use "list.size() == 0" instead.
• ensureCapacity(int) Define the expected capacity in the constructor.
• indexOf(Object)/lastIndexOf(Object) You have to do them manually. Use "list.toArray()" to get the stored objects, cycle through them and test for equality.
• addAll(Collection) Add all elements of the collection singlely.

Constructor Summary

Constructors

Constructor and Description
ArrayList() Creates an ArrayList with the initial capacity of 10 and a growth factor of 75%
ArrayList(int initialCapacity) creates an ArrayList with the given initial capacity and a growth factor of 75%
ArrayList(int initialCapacity, int growthFactor) Creates a new ArrayList

Method Summary

Methods

Modifier and Type	Method and Description
void	add(int index, Object element) Inserts the given element at the defined position.
void	add(Object element) Stores the given element in this list.
void	clear() Removes all of the elements from this list.
boolean	contains(Object element) Determines whether the given element is stored in this list.
Object	get(int index) Returns the element at the specified position in this list.
Object[]	getInternalArray() Retrieves the internal array - use with care! This method allows to access stored objects without creating an intermediate array.
int	indexOf(Object element) Retrieves the index of the given object.
Object	remove(int index) Removes the element at the specified position in this list.
boolean	remove(Object element) Removes the given element.
Object	set(int index, Object element) Replaces the element at the specified position in this list with the specified element.
int	size() Retrieves the current size of this array list.
Object[]	toArray() Returns all stored elements as an array.
Object[]	toArray(Object[] target) Returns all stored elements in the given array.
String	toString() Returns String containing the String representations of all objects of this list.
void	trimToSize() Trims the capacity of this ArrayList instance to be the list's current size.

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayList

public ArrayList()

Creates an ArrayList with the initial capacity of 10 and a growth factor of 75%

ArrayList

public ArrayList(int initialCapacity)

creates an ArrayList with the given initial capacity and a growth factor of 75%

Parameters:

initialCapacity - the capacity of this array list.

ArrayList

public ArrayList(int initialCapacity,
         int growthFactor)

Creates a new ArrayList

Parameters:

initialCapacity - the capacity of this array list.

growthFactor - the factor in % for increasing the capacity when there's not enough room in this list anymore

Method Detail

size

public int size()

Retrieves the current size of this array list.

Returns:

the number of stored elements in this list.

contains

public boolean contains(Object element)

Determines whether the given element is stored in this list.

Parameters:

element - the element which might be stored in this list

Returns:

true when the given element is stored in this list

Throws:

IllegalArgumentException - when the given element is null

See Also:

remove(Object)

indexOf

public int indexOf(Object element)

Retrieves the index of the given object.

Parameters:

element - the object which is part of this list.

Returns:

the index of the object or -1 when the object is not part of this list.

Throws:

IllegalArgumentException - when the given element is null

get

public Object get(int index)

Returns the element at the specified position in this list.

Parameters:

index - the position of the desired element.

Returns:

the element stored at the given position

Throws:

IndexOutOfBoundsException - when the index < 0 || index >= size()

remove

public Object remove(int index)

Removes the element at the specified position in this list.

Parameters:

index - the position of the desired element.

Returns:

the element stored at the given position

Throws:

IndexOutOfBoundsException - when the index < 0 || index >= size()

remove

public boolean remove(Object element)

Removes the given element.

Parameters:

element - the element which should be removed.

Returns:

true when the element was found in this list.

Throws:

IllegalArgumentException - when the given element is null

See Also:

contains(Object)

clear

public void clear()

Removes all of the elements from this list. The list will be empty after this call returns.

add

public void add(Object element)

Stores the given element in this list.

Parameters:

element - the element which should be appended to this list.

Throws:

IllegalArgumentException - when the given element is null

See Also:

add( int, Object )

add

public void add(int index,
       Object element)

Inserts the given element at the defined position. Any following elements are shifted one position to the back.

Parameters:

index - the position at which the element should be inserted, use 0 when the element should be inserted in the front of this list.

element - the element which should be inserted

Throws:

IllegalArgumentException - when the given element is null

IndexOutOfBoundsException - when the index < 0 || index >= size()

set

public Object set(int index,
         Object element)

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

Parameters:

index - the position of the element, the first element has the index 0.

element - the element which should be set

Returns:

the replaced element

Throws:

IndexOutOfBoundsException - when the index < 0 || index >= size()

toString

public String toString()

Returns String containing the String representations of all objects of this list.

Overrides:

toString in class Object

Returns:

the stored elements in a String representation.

toArray

public Object[] toArray()

Returns all stored elements as an array.

Returns:

the stored elements as an array.

toArray

public Object[] toArray(Object[] target)

Returns all stored elements in the given array.

Parameters:

target - the array in which the stored elements should be copied.

Returns:

the stored elements of this list

trimToSize

public void trimToSize()

Trims the capacity of this ArrayList instance to be the list's current size. An application can use this operation to minimize the storage of an ArrayList instance.

getInternalArray

public Object[] getInternalArray()

Retrieves the internal array - use with care! This method allows to access stored objects without creating an intermediate array. You really should refrain from changing any elements in the returned array unless you are 110% sure about what you are doing. It is safe to cycle through this array to access it's elements, though. Note that some array positions might contain null. Also note that the internal array is changed whenever this list has to be increased.

Returns:

the internal array