org.apache.poi.util
Class ArrayUtil

java.lang.Object
  org.apache.poi.util.ArrayUtil

public class ArrayUtil
extends java.lang.Object

Utility classes for dealing with arrays.

Author:

Glen Stampoultzis

Constructor Summary

ArrayUtil()

Method Summary

static void	arraycopy(byte[] src, int src_position, byte[] dst, int dst_position, int length) This is really a debugging version of System.arraycopy().
static void	arrayMoveWithin(java.lang.Object[] array, int moveFrom, int moveTo, int numToMove) Moves a number of entries in an array to another point in the array, shifting those inbetween as required.
static byte[]	copyOf(byte[] source, int newLength) Copies the specified array, truncating or padding with zeros (if necessary) so the copy has the specified length.
static byte[]	copyOfRange(byte[] original, int from, int to) Copies the specified range of the specified array into a new array.

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayUtil

public ArrayUtil()

Method Detail

arraycopy

public static void arraycopy(byte[] src,
                             int src_position,
                             byte[] dst,
                             int dst_position,
                             int length)

This is really a debugging version of System.arraycopy(). Use it to provide better exception messages when copying arrays around. For production use it's better to use the original for speed.

arrayMoveWithin

public static void arrayMoveWithin(java.lang.Object[] array,
                                   int moveFrom,
                                   int moveTo,
                                   int numToMove)

Moves a number of entries in an array to another point in the array, shifting those inbetween as required.

Parameters:

array - The array to alter

moveFrom - The (0 based) index of the first entry to move

moveTo - The (0 based) index of the positition to move to

numToMove - The number of entries to move

copyOf

public static byte[] copyOf(byte[] source,
                            int newLength)

Copies the specified array, truncating or padding with zeros (if necessary) so the copy has the specified length. This method is temporary replace for Arrays.copyOf() until we start to require JDK 1.6.

Parameters:

source - the array to be copied

newLength - the length of the copy to be returned

Returns:

a copy of the original array, truncated or padded with zeros to obtain the specified length

Throws:

java.lang.NegativeArraySizeException - if newLength is negative

java.lang.NullPointerException - if original is null

copyOfRange

public static byte[] copyOfRange(byte[] original,
                                 int from,
                                 int to)

Copies the specified range of the specified array into a new array. The initial index of the range (from) must lie between zero and original.length, inclusive. The value at original[from] is placed into the initial element of the copy (unless from == original.length or from == to). Values from subsequent elements in the original array are placed into subsequent elements in the copy. The final index of the range (to), which must be greater than or equal to from, may be greater than original.length, in which case (byte)0 is placed in all elements of the copy whose index is greater than or equal to original.length - from. The length of the returned array will be to - from. This method is temporary replace for Arrays.copyOfRange() until we start to require JDK 1.6.

Parameters:

original - the array from which a range is to be copied

from - the initial index of the range to be copied, inclusive

to - the final index of the range to be copied, exclusive. (This index may lie outside the array.)

Returns:

a new array containing the specified range from the original array, truncated or padded with zeros to obtain the required length

Throws:

java.lang.ArrayIndexOutOfBoundsException - if from < 0 or from > original.length()

java.lang.IllegalArgumentException - if from > to

java.lang.NullPointerException - if original is null

Since:

1.6