org.h2.util
Class ByteUtils

java.lang.Object
  org.h2.util.ByteUtils

public class ByteUtils
extends java.lang.Object

This utility class contains functions related to byte arrays.

Method Summary

static void	clear(byte[] buff) Set all elements of the array to zero.
static byte[]	cloneByteArray(byte[] b) Create a new byte array and copy all the data.
static int	compareNotNull(byte[] data1, byte[] data2) Compare the contents of two byte arrays.
static boolean	compareSecure(byte[] test, byte[] good) Compare two byte arrays.
static java.lang.String	convertBytesToString(byte[] value) Convert a byte array to a hex encoded string.
static java.lang.String	convertBytesToString(byte[] value, int len) Convert a byte array to a hex encoded string.
static byte[]	convertStringToBytes(java.lang.String s) Convert a hex encoded string to a byte array.
static byte[]	copy(byte[] source, byte[] target) Copy the contents of the source array to the target array.
static int	getByteArrayHash(byte[] value) Calculate the hash code of the given byte array.
static int	indexOf(byte[] bytes, byte[] pattern, int start) Calculate the index of the first occurrence of the pattern in the byte array, starting with the given index.
static long	readLong(byte[] buff, int pos) Read a long value from the byte array at the given position.

Methods inherited from class java.lang.Object

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

Method Detail

readLong

public static long readLong(byte[] buff,
                            int pos)

Read a long value from the byte array at the given position. The most significant byte is read first.

Parameters:

buff - the byte array

pos - the position

Returns:

the value

indexOf

public static int indexOf(byte[] bytes,
                          byte[] pattern,
                          int start)

Calculate the index of the first occurrence of the pattern in the byte array, starting with the given index. This methods returns -1 if the pattern has not been found, and the start position if the pattern is empty.

Parameters:

bytes - the byte array

pattern - the pattern

start - the start index from where to search

Returns:

the index

convertStringToBytes

public static byte[] convertStringToBytes(java.lang.String s)
                                   throws java.sql.SQLException

Convert a hex encoded string to a byte array.

Parameters:

s - the hex encoded string

Returns:

the byte array

Throws:

java.sql.SQLException

getByteArrayHash

public static int getByteArrayHash(byte[] value)

Calculate the hash code of the given byte array.

Parameters:

value - the byte array

Returns:

the hash code

convertBytesToString

public static java.lang.String convertBytesToString(byte[] value)

Convert a byte array to a hex encoded string.

Parameters:

value - the byte array

Returns:

the hex encoded string

convertBytesToString

public static java.lang.String convertBytesToString(byte[] value,
                                                    int len)

Convert a byte array to a hex encoded string.

Parameters:

value - the byte array

len - the number of bytes to encode

Returns:

the hex encoded string

compareSecure

public static boolean compareSecure(byte[] test,
                                    byte[] good)

Compare two byte arrays. This method will always loop over all bytes and doesn't use conditional operations in the loop to make sure an attacker can not use a timing attack when trying out passwords.

Parameters:

test - the first array

good - the second array

Returns:

true if both byte arrays contain the same bytes

clear

public static void clear(byte[] buff)

Set all elements of the array to zero.

Parameters:

buff - the byte array

compareNotNull

public static int compareNotNull(byte[] data1,
                                 byte[] data2)

Compare the contents of two byte arrays. If the content or length of the first array is smaller than the second array, -1 is returned. If the content or length of the second array is smaller than the first array, 1 is returned. If the contents and lengths are the same, 0 is returned.

Parameters:

data1 - the first byte array (must not be null)

data2 - the second byte array (must not be null)

Returns:

the result of the comparison (-1, 1 or 0)

copy

public static byte[] copy(byte[] source,
                          byte[] target)

Copy the contents of the source array to the target array. If the size if the target array is too small, a larger array is created.

Parameters:

source - the source array

target - the target array

Returns:

the target array or a new one if the target array was too small

cloneByteArray

public static byte[] cloneByteArray(byte[] b)

Create a new byte array and copy all the data. If the size of the byte array is zero, the same array is returned.

Parameters:

b - the byte array (may not be null)

Returns:

a new byte array