gnu.java.zrtp.utils

Class ZrtpUtils

java.lang.Object

gnu.java.zrtp.utils.ZrtpUtils

public class ZrtpUtils
extends Object

Some helpful functions, all public static

Author:

Werner Dittmann <Werner.Dittmann@t-online.de>

Constructor Summary

Constructors

Constructor and Description
ZrtpUtils()

Method Summary

Modifier and Type	Method and Description
static int	byteArrayCompare(byte[] arg1, byte[] arg2, int length)
static char[]	bytesToHexString(byte[] in, int length)
static void	hexdump(String title, byte[] buf, int len) Dump a buffer in hex and readable format.
static byte[]	int32ToArray(int data) Convert a 32 bit integer into a byte array, network order.
static void	int32ToArrayInPlace(int data, byte[] buffer, int offset) Convert a 32 bit integer into a byte array, network order.
static int	readInt(byte[] buffer, int offset) Extract four bytes from a buffer and convert into an integer.
static byte[]	readRegion(byte[] buffer, int offset, int length) Read a byte region from specified offset with specified length
static short	readShort(byte[] buffer, int offset) Extract two bytes from a buffer and convert into a short integer.
static byte[]	short16ToArray(int data) Convert a 16 bit integer into a byte array, network order.
static void	short16ToArrayInPlace(int data, byte[] buffer, int offset) Convert a 16 bit integer into a byte array, network order.

Methods inherited from class java.lang.Object

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

Constructor Detail

ZrtpUtils

public ZrtpUtils()

Method Detail

int32ToArray

public static byte[] int32ToArray(int data)

Convert a 32 bit integer into a byte array, network order.

Parameters:

data - the 32 bit integer to send over the network

Returns:

the byte array conating the converted integer

int32ToArrayInPlace

public static void int32ToArrayInPlace(int data,
                                       byte[] buffer,
                                       int offset)

Convert a 32 bit integer into a byte array, network order. This method places the converted four bytes into the buffer starting at the given offset.

Parameters:

data - the 32 bit integer to send over the network

buffer - the byte array that receives the converted integer

offset - the offset into the buffer

short16ToArray

public static byte[] short16ToArray(int data)

Convert a 16 bit integer into a byte array, network order.

Parameters:

data - the 16 bit integer to send over the network

Returns:

the byte array conating the converted short integer

short16ToArrayInPlace

public static void short16ToArrayInPlace(int data,
                                         byte[] buffer,
                                         int offset)

Convert a 16 bit integer into a byte array, network order.

Parameters:

data - the 16 bit integer to send over the network

readShort

public static short readShort(byte[] buffer,
                              int offset)

Extract two bytes from a buffer and convert into a short integer. The method reads 2 bytes from the buffer starting at the specified offset and converts it into a short integer. The buffer contains the bytes in network order.

Parameters:

buffer - The buffer containing the bytes in network order.

offset - Offset into buffer.

readInt

public static int readInt(byte[] buffer,
                          int offset)

Extract four bytes from a buffer and convert into an integer. The method reads 4 bytes from the buffer starting at the specified offset and converts it into a integer. The buffer contains the bytes in network order.

Parameters:

buffer - The buffer containing the bytes in network order.

offset - Offset into buffer.

readRegion

public static byte[] readRegion(byte[] buffer,
                                int offset,
                                int length)

Read a byte region from specified offset with specified length

Parameters:

buffer - the buffer to copy from

offset - start offset of the region to be read

length - length of the region to be read

Returns:

byte array of [offset, offset + length)

hexdump

public static void hexdump(String title,
                           byte[] buf,
                           int len)

Dump a buffer in hex and readable format.

Parameters:

title - Printed at the beginning of the dump

buf - Byte buffer to dump

len - Number of bytes to dump, should be less or equal the buffer length

bytesToHexString

public static char[] bytesToHexString(byte[] in,
                                      int length)

byteArrayCompare

public static int byteArrayCompare(byte[] arg1,
                                   byte[] arg2,
                                   int length)