com.integpg.system

Class ArrayUtils

java.lang.Object

com.integpg.system.ArrayUtils

public class ArrayUtils
extends Object

This class implements methods to manage arrays. This includes comparison, copying, filling and inserting and removing simple data types into byte arrays. Simple data types are stored in byte arrays in big-endian format.

Method Summary

Modifier and Type	Method and Description
static boolean	arrayComp(Object array1, int offset1, Object array2, int offset2, int length) Compares length elements in array1 at offset1 with the elements in array2 at offset2.
static int	arraycopy(Object src, int src_position, Object dst, int dst_position, int length) Copies length elements from the src array at index src_position to the dst array at index dst_position.
static void	arrayCopyUnequal(Object fromArray, int fromOffset, Object toArray, int toOffset, int length) Copies length common lower element bytes from fromArray at fromOffset into toArray at toOffset.
static void	arrayFill(byte[] thisArray, int fromIndex, int toIndex, byte fillValue) Fills thisArray from fromIndex to toIndex with fillValue.
static int	getInt(byte[] thisArray, int offset) Reads an int value from a byte array.
static long	getLong(byte[] thisArray, int offset) Reads a long value from a byte array.
static short	getShort(byte[] thisArray, int offset) Reads a short value from a byte array.
static byte[]	setInt(byte[] thisArray, int offset, int value) Writes an int value value to byte array thisArray starting at offset offset.
static byte[]	setLong(byte[] thisArray, int offset, long value) Writes a long value value to byte array thisArray starting at offset offset.
static byte[]	setShort(byte[] thisArray, int offset, short value) Writes a short value value to byte array thisArray starting at offset offset.
static int	swapEndian(int value) Reverses the byte order of a value.
static long	swapEndian(long value) Reverses the byte order of a value.
static short	swapEndian(short value) Reverses the byte order of a value.

Methods inherited from class java.lang.Object

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

Method Detail

arraycopy

public static int arraycopy(Object src,
                            int src_position,
                            Object dst,
                            int dst_position,
                            int length)

Copies length elements from the src array at index src_position to the dst array at index dst_position. The src and dst arrays must be of the same type. This is similar to java.lang.System.arraycopy(), but more restrictive. This allows it to be slightly faster, and calls one less method than the same array copy performed through the java.lang.System class.

Parameters:

src - source array

src_position - starting index in source array

dst - target array

dst_position - starting index in target array

length - number of elements to copy

Returns:

0 under normal operation. If both dst and src are arrays of references, and are not the same type, returns -1.

arrayCopyUnequal

public static void arrayCopyUnequal(Object fromArray,
                                    int fromOffset,
                                    Object toArray,
                                    int toOffset,
                                    int length)

Copies length common lower element bytes from fromArray at fromOffset into toArray at toOffset.
If the destination element has more bytes than the source element, the upper bytes of each element are set to zero.
If the destination element has less bytes than the source element, the upper bytes are truncated.

Parameters:

fromArray - source array

fromOffset - starting index in source array

toArray - target array

toOffset - starting index in target array

length - number of elements to copy

arrayComp

public static boolean arrayComp(Object array1,
                                int offset1,
                                Object array2,
                                int offset2,
                                int length)

Compares length elements in array1 at offset1 with the elements in array2 at offset2.

Parameters:

array1 - source array

offset1 - starting index in source array

array2 - target array

offset2 - starting index in target array

length - number of elements to compare

Returns:

false if all elements are not the same

arrayFill

public static void arrayFill(byte[] thisArray,
                             int fromIndex,
                             int toIndex,
                             byte fillValue)

Fills thisArray from fromIndex to toIndex with fillValue.

Parameters:

thisArray - target array

fromIndex - starting index for fill, inclusive

toIndex - ending index for fill, exclusive

fillValue - value to fill array

setShort

public static byte[] setShort(byte[] thisArray,
                              int offset,
                              short value)

Writes a short value value to byte array thisArray starting at offset offset. The values are stored in the array in Big Endian form.

Parameters:

thisArray - array that will be modified

offset - starting offset

value - value to be written

Returns:

array reference to thisArray

setInt

public static byte[] setInt(byte[] thisArray,
                            int offset,
                            int value)

Writes an int value value to byte array thisArray starting at offset offset. The values are stored in the array in Big Endian form.

Parameters:

thisArray - array that will be modified

offset - starting offset

value - value to be written

Returns:

array reference to thisArray

setLong

public static byte[] setLong(byte[] thisArray,
                             int offset,
                             long value)

Writes a long value value to byte array thisArray starting at offset offset. The values are stored in the array in Big Endian form.

Parameters:

thisArray - array that will be modified

offset - starting offset

value - value to be written

Returns:

array reference to thisArray

getShort

public static short getShort(byte[] thisArray,
                             int offset)

Reads a short value from a byte array. The values extracted are assumed to be in Big Endian Form.

Parameters:

thisArray - array containing the value

offset - starting offset

Returns:

value read

getInt

public static int getInt(byte[] thisArray,
                         int offset)

Reads an int value from a byte array. The values extracted are assumed to be in Big Endian Form.

Parameters:

thisArray - array containing the value

offset - starting offset

Returns:

value read

getLong

public static long getLong(byte[] thisArray,
                           int offset)

Reads a long value from a byte array. The values extracted are assumed to be in Big Endian Form.

Parameters:

thisArray - array containing the value

offset - starting offset

Returns:

value read

swapEndian

public static short swapEndian(short value)

Reverses the byte order of a value. A little endian value is returned as big endian (system default). A system default big endian value is returned in little endian representation. This is very useful in dealing with protocol byte order differences.

Parameters:

value - short value (2 bytes)

Returns:

short value with byte order reversed

swapEndian

public static int swapEndian(int value)

Reverses the byte order of a value. A little endian value is returned as big endian (system default). A system default big endian value is returned in little endian representation. This is very useful in dealing with protocol byte order differences.

Parameters:

value - int value (4 bytes)

Returns:

int value with byte order reversed

swapEndian

public static long swapEndian(long value)

Reverses the byte order of a value. A little endian value is returned as big endian (system default). A system default big endian value is returned in little endian representation. This is very useful in dealing with protocol byte order differences.

Parameters:

value - long value (8 bytes)

Returns:

long value with byte order reversed