com.xmlmind.util
Class ArrayUtil

java.lang.Object
  com.xmlmind.util.ArrayUtil

public final class ArrayUtil
extends java.lang.Object

A collection of utility functions (static methods) operating on arrays. Complements what's found in java.util.Arrays.

Method Summary

static <T> T[]	append(T[] list, T item) Inserts specified item in specified array at the end of specified array.
static <T> int	find(T[] list, T item) Searches specified array for specified item.
static <T> int	indexOf(T[] list, T item) Searches specified array for specified item.
static <T> T[]	insert(T[] list, int index, T item) Equivalent to insert(list, index, new T[] { item}).
static <T> T[]	insert(T[] list, int index, T[] items) Inserts specified items in specified array at specified index.
static <T> T[]	prepend(T[] list, T item) Inserts specified item in specified array at the beginning of specified array.
static <T> T[]	remove(T[] list, T item) Remove specified item from specified array.
static <T> T[]	removeAt(T[] list, int index) Equivalent to remove(list, index, 1).
static <T> T[]	removeAt(T[] list, int index, int count) Removes a range of items found at specified index from specified array.
static <T> void	reverse(T[] list) Reverses the order of the items in the specified array.
static <T> T[]	subArray(T[] list, int start) Equivalent to subArray(list, start, list.length).
static <T> T[]	subArray(T[] list, int start, int end) Returns a sub-array of specified array.
static <T> T[]	trimToSize(T[] list, int listSize) Returns specified array if its length is equal to specified size; otherwise returns a copy of specified array having specified size.

Methods inherited from class java.lang.Object

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

Method Detail

trimToSize

public static final <T> T[] trimToSize(T[] list,
                                       int listSize)

Returns specified array if its length is equal to specified size; otherwise returns a copy of specified array having specified size.

Type Parameters:

T - the type of the components of the array

Parameters:

list - array whose size needs to be adjusted

listSize - the size of the returned array

Returns:

an array having listSize components

subArray

public static final <T> T[] subArray(T[] list,
                                     int start)

Equivalent to subArray(list, start, list.length).

subArray

public static final <T> T[] subArray(T[] list,
                                     int start,
                                     int end)

Returns a sub-array of specified array.

Type Parameters:

T - the type of the components of the array

Parameters:

list - the array

start - the begin index, inclusive

end - the end index, exclusive

Returns:

the sub-array

Throws:

java.lang.IndexOutOfBoundsException - if start or end are negative, if end is greater than list.length or if start is greater than end

insert

public static final <T> T[] insert(T[] list,
                                   int index,
                                   T item)

Equivalent to insert(list, index, new T[] { item}).

insert

public static final <T> T[] insert(T[] list,
                                   int index,
                                   T[] items)

Inserts specified items in specified array at specified index.

Type Parameters:

T - the type of the components of the array

Parameters:

list - list to be modified

index - items are inserted at this position.

Note that index may be equal to the size of the array. This means: insert at end.

items - items to be inserted

Returns:

new array having original size+items.length components

prepend

public static final <T> T[] prepend(T[] list,
                                    T item)

Inserts specified item in specified array at the beginning of specified array.

Type Parameters:

T - the type of the components of the array

Parameters:

list - list to be modified

item - item to be inserted

Returns:

new array having original size+1 components

append

public static final <T> T[] append(T[] list,
                                   T item)

Inserts specified item in specified array at the end of specified array.

Type Parameters:

T - the type of the components of the array

Parameters:

list - list to be modified

item - item to be inserted

Returns:

new array having original size+1 components

remove

public static final <T> T[] remove(T[] list,
                                   T item)

Remove specified item from specified array. Items are compared using equals() and not == (using indexOf(T[], T)).

Type Parameters:

T - the type of the components of the array

Parameters:

list - list to be modified

item - item to be removed

Returns:

new array having original size-1 components

indexOf

public static final <T> int indexOf(T[] list,
                                    T item)

Searches specified array for specified item. Unlike find(T[], T), items are compared using equals() and not ==.

Type Parameters:

T - the type of the components of the array

Parameters:

list - a list possibly containing item

item - searched item

Returns:

the index of searched item if found; -1 otherwise

find

public static final <T> int find(T[] list,
                                 T item)

Searches specified array for specified item. Unlike indexOf(T[], T), items are compared using == and not equals().

Type Parameters:

T - the type of the components of the array

Parameters:

list - a list possibly containing item

item - searched item

Returns:

the index of searched item if found; -1 otherwise

removeAt

public static final <T> T[] removeAt(T[] list,
                                     int index)

Equivalent to remove(list, index, 1).

removeAt

public static final <T> T[] removeAt(T[] list,
                                     int index,
                                     int count)

Removes a range of items found at specified index from specified array.

Type Parameters:

T - the type of the components of the array

Parameters:

list - list to be modified

index - items are removed at this position

count - number of items to be removed

Returns:

new array having original size-count

reverse

public static final <T> void reverse(T[] list)

Reverses the order of the items in the specified array.