net.sourceforge.apphere.util
Class BytesUtil

java.lang.Object
  net.sourceforge.apphere.util.BytesUtil

public class BytesUtil

extends java.lang.Object

Provides functions to easily convert short, int, string and float into/from byte[]

.
• short -- 2 bytes
• int -- 4 bytes
• float -- 4 bytes
• long -- 8 bytes
• double -- 8 bytes
• string -- when stored in byte[], the first cell is the length of the string. (Also notice that string longer than 255 will be truncated.

Field Summary

static int	BYTE_LEN
static int	DOUBLE_LEN
static int	FLOAT_LEN
static int	INT_LEN
static int	LONG_LEN
static int	SHORT_LEN

Constructor Summary

BytesUtil()

Method Summary

static double	bytesToDouble(byte[] bytes, int startIndex) Given an array of bytes, convert it to a double, least significant byte is stored in the beginning.
static float	bytesToFloat(byte[] bytes, int startIndex) Given a byte array, restore it as an int
static int	bytesToInt(byte[] bytes, int startIndex) Given a byte array, restore it as an int
static long	bytesToLong(byte[] bytes, int startIndex) Given an array of bytes, convert it to a long, least significant byte is stored in the beginning.
static short	bytesToShort(byte[] bytes, int startIndex) Given a byte array, restore it as a short
static java.lang.String	bytesToString(byte[] bytes, int startIndex) Given a byte array, restore a String out of it.
static int	doubleToBytes(double dnum, byte[] bytes, int startIndex) Given a double, convert it into a byte array
static int	floatToBytes(float fnum, byte[] bytes, int startIndex) translate float into bytes, stored in byte array starting from startIndex
static int	intToBytes(int num, byte[] bytes, int startIndex) translate int into bytes, stored in byte array starting from startIndex
static int	longToBytes(long lnum, byte[] bytes, int startIndex) Given a long, convert it into a byte array
static int	shortToBytes(short num, byte[] bytes, int startIndex) translate short into bytes, stored in byte array starting from startIndex
static int	stringToBytes(java.lang.String str, byte[] bytes, int startIndex) Give a String less than 255 bytes, store it as byte array, starting with the length of the string.

Methods inherited from class java.lang.Object

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

Field Detail

BYTE_LEN

public static final int BYTE_LEN

See Also:

Constant Field Values

SHORT_LEN

public static final int SHORT_LEN

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Constant Field Values

INT_LEN

public static final int INT_LEN

See Also:

Constant Field Values

FLOAT_LEN

public static final int FLOAT_LEN

See Also:

Constant Field Values

LONG_LEN

public static final int LONG_LEN

See Also:

Constant Field Values

DOUBLE_LEN

public static final int DOUBLE_LEN

See Also:

Constant Field Values

Constructor Detail

BytesUtil

public BytesUtil()

Method Detail

intToBytes

public static int intToBytes(int num,
                             byte[] bytes,
                             int startIndex)

translate int into bytes, stored in byte array starting from startIndex

Parameters:

num - the integer to be translated

startIndex - starting to store in this index

Returns:

the index of the cell after storing the number.

bytesToInt

public static int bytesToInt(byte[] bytes,
                             int startIndex)

Given a byte array, restore it as an int

Parameters:

bytes - the byte array

startIndex - the starting index of the place the int is stored

floatToBytes

public static int floatToBytes(float fnum,
                               byte[] bytes,
                               int startIndex)

translate float into bytes, stored in byte array starting from startIndex

Parameters:

startIndex - starting to store in this index

Returns:

the index of the cell after storing the number.

bytesToFloat

public static float bytesToFloat(byte[] bytes,
                                 int startIndex)

Given a byte array, restore it as an int

Parameters:

bytes - the byte array

startIndex - the starting index of the place the int is stored

shortToBytes

public static int shortToBytes(short num,
                               byte[] bytes,
                               int startIndex)

translate short into bytes, stored in byte array starting from startIndex

Parameters:

num - the short to be translated

startIndex - starting to store in this index

Returns:

the index of the cell after storing the number.

bytesToShort

public static short bytesToShort(byte[] bytes,
                                 int startIndex)

Given a byte array, restore it as a short

Parameters:

bytes - the byte array

startIndex - the starting index of the place the int is stored

stringToBytes

public static int stringToBytes(java.lang.String str,
                                byte[] bytes,
                                int startIndex)

Give a String less than 255 bytes, store it as byte array, starting with the length of the string. If the length of the String is longer than 255, a warning is generated, and the string will be truncated.

Parameters:

str - the string that is less than 255 bytes

bytes - the byte array

startIndex - the starting index where the string will be stored.

Returns:

the index of the array after storing this string

bytesToString

public static java.lang.String bytesToString(byte[] bytes,
                                             int startIndex)

Given a byte array, restore a String out of it. the first cell stores the length of the String

Parameters:

bytes - the byte array

startIndex - the starting index where the string is stored, the first cell stores the length

Returns:

the string out of the byte array.

longToBytes

public static int longToBytes(long lnum,
                              byte[] bytes,
                              int startIndex)

Given a long, convert it into a byte array

Parameters:

lnum - the long given to convert

bytes - the bytes where to store the result

startIndex - the starting index of the array where the result is stored.

Returns:

the index of the array after storing this long

bytesToLong

public static long bytesToLong(byte[] bytes,
                               int startIndex)

Given an array of bytes, convert it to a long, least significant byte is stored in the beginning.

Parameters:

bytes - the byte array

startIndex - the starting index of the array where the long is stored.

Returns:

the long result.

doubleToBytes

public static int doubleToBytes(double dnum,
                                byte[] bytes,
                                int startIndex)

Given a double, convert it into a byte array

Parameters:

dnum - the double given to convert

bytes - the bytes where to store the result

startIndex - the starting index of the array where the result is stored.

Returns:

the index of the array after storing this double

bytesToDouble

public static double bytesToDouble(byte[] bytes,
                                   int startIndex)

Given an array of bytes, convert it to a double, least significant byte is stored in the beginning.

Parameters:

bytes - the byte array

startIndex - the starting index of the array where the long is stored.

Returns:

the double result.