Module openj9.dataaccess

Package com.ibm.dataaccess

Class ByteArrayUnmarshaller

java.lang.Object

com.ibm.dataaccess.ByteArrayUnmarshaller

public final class ByteArrayUnmarshaller
extends Object

Conversion routines to unmarshall Java binary types (short, int, long, float, double) from byte arrays.

With sign extensions enabled, the marshalled data is interpreted as signed and the data will be appropriately converted into the return type container. With sign extensions disabled, unfilled bits in the container will be set to zero. For example, -1 as one signed byte is 0xFF. Using readShort with signExtend true, the resultant short will contain 0xFFFF, which is -1 in Java's signed format. With signExtend false, the resultant short will contain 0x00FF, which is 255.

Method Summary

Modifier and Type	Method	Description
static double	readDouble(byte[] byteArray, int offset, boolean bigEndian)	Returns a double value copied from eight consecutive bytes of the byte array starting at the offset.
static float	readFloat(byte[] byteArray, int offset, boolean bigEndian)	Returns a float value copied from four consecutive bytes of the byte array starting at the offset.
static int	readInt(byte[] byteArray, int offset, boolean bigEndian)	Returns an int value copied from four consecutive bytes starting at the offset.
static int	readInt(byte[] byteArray, int offset, boolean bigEndian, int numBytes, boolean signExtend)	Returns an int value copied from zero to four consecutive bytes of the byte array starting at the offset.
static long	readLong(byte[] byteArray, int offset, boolean bigEndian)	Returns a long value copied from eight consecutive bytes of the byte array starting at the offset.
static long	readLong(byte[] byteArray, int offset, boolean bigEndian, int numBytes, boolean signExtend)	Returns a long value copied from zero to eight consecutive bytes of the byte array starting at the offset.
static short	readShort(byte[] byteArray, int offset, boolean bigEndian)	Returns a short value copied from two consecutive bytes of the byte array starting at the offset.
static short	readShort(byte[] byteArray, int offset, boolean bigEndian, int numBytes, boolean signExtend)	Returns a short value copied from zero to two consecutive bytes of the byte array starting at the offset.

Methods declared in class java.lang.Object

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

Method Details

readShort

public static short readShort(byte[] byteArray,
 int offset,
 boolean bigEndian)

Returns a short value copied from two consecutive bytes of the byte array starting at the offset.

Parameters:

byteArray - source

offset - offset in the byte array

bigEndian - if false the bytes will be copied in reverse (little endian) order

Returns:

short

Throws:

NullPointerException - if byteArray is null

ArrayIndexOutOfBoundsException - if an invalid array access occurs

readShort

public static short readShort(byte[] byteArray,
 int offset,
 boolean bigEndian,
 int numBytes,
 boolean signExtend)

Returns a short value copied from zero to two consecutive bytes of the byte array starting at the offset.

Parameters:

byteArray - source

offset - offset in the byte array

bigEndian - if false the bytes will be copied in reverse (little endian) order

numBytes - the number of bytes to unmarshall, must be 0-2 inclusive

signExtend - if true and numBytes < 2 then the topmost bytes of the returned short will be sign extended

Returns:

long

Throws:

NullPointerException - if byteArray is null

IllegalArgumentException - if numBytes < 0 or numBytes > 2

ArrayIndexOutOfBoundsException - if an invalid array access occurs

readInt

public static int readInt(byte[] byteArray,
 int offset,
 boolean bigEndian)

Returns an int value copied from four consecutive bytes starting at the offset.

Parameters:

byteArray - source

offset - offset in the byte array

bigEndian - if false the bytes will be copied in reverse (little endian) order

Returns:

int

Throws:

NullPointerException - if byteArray is null

ArrayIndexOutOfBoundsException - if an invalid array access occurs

readInt

public static int readInt(byte[] byteArray,
 int offset,
 boolean bigEndian,
 int numBytes,
 boolean signExtend)

Returns an int value copied from zero to four consecutive bytes of the byte array starting at the offset.

Parameters:

byteArray - source

offset - offset in the byte array

bigEndian - if false the bytes will be copied in reverse (little endian) order

numBytes - the number of bytes to unmarshall, must be 0-4 inclusive

signExtend - if true and numBytes < 4 then the topmost bytes of the returned int will be sign extended

Returns:

int

Throws:

NullPointerException - if byteArray is null

IllegalArgumentException - if numBytes < 0 or numBytes > 4

ArrayIndexOutOfBoundsException - if an invalid array access occurs

readLong

public static long readLong(byte[] byteArray,
 int offset,
 boolean bigEndian)

Returns a long value copied from eight consecutive bytes of the byte array starting at the offset.

Parameters:

byteArray - source

offset - offset in the byte array

bigEndian - if false the bytes will be copied in reverse (little endian) order

Returns:

long

Throws:

NullPointerException - if byteArray is null

ArrayIndexOutOfBoundsException - if an invalid array access occurs

readLong

public static long readLong(byte[] byteArray,
 int offset,
 boolean bigEndian,
 int numBytes,
 boolean signExtend)

Returns a long value copied from zero to eight consecutive bytes of the byte array starting at the offset.

Parameters:

byteArray - source

offset - offset in the byte array

bigEndian - if false the bytes will be copied in reverse (little endian) order

numBytes - the number of bytes to unmarshall, must be 0-8 inclusive

signExtend - if true and numBytes < 8 then the topmost bytes of the returned long will be sign extended

Returns:

long

Throws:

NullPointerException - if byteArray is null

IllegalArgumentException - if numBytes < 0 or numBytes > 8

ArrayIndexOutOfBoundsException - if an invalid array access occurs

readFloat

public static float readFloat(byte[] byteArray,
 int offset,
 boolean bigEndian)

Returns a float value copied from four consecutive bytes of the byte array starting at the offset.

Parameters:

byteArray - source

offset - offset in the byte array

bigEndian - if false the bytes will be copied in reverse (little endian) order

Returns:

float

Throws:

NullPointerException - if byteArray is null

ArrayIndexOutOfBoundsException - if an invalid array access occurs

readDouble

public static double readDouble(byte[] byteArray,
 int offset,
 boolean bigEndian)

Returns a double value copied from eight consecutive bytes of the byte array starting at the offset.

Parameters:

byteArray - source

offset - offset in the byte array

bigEndian - if false the bytes will be copied in reverse (little endian) order

Returns:

double

Throws:

NullPointerException - if byteArray is null

ArrayIndexOutOfBoundsException - if an invalid array access occurs