ch.hevs.isi.utils

Class Utility

java.lang.Object

ch.hevs.isi.utils.Utility

public class Utility
extends java.lang.Object

This class contains some useful Java methods to manipulate data.

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.Random	rnd Object to get some random values...
static int	TCP_BUFFER_SIZE Default size for the TCP input stream

Constructor Summary

Constructors

Constructor and Description
Utility()

Method Summary

Modifier and Type	Method and Description
static java.lang.Float	bytesToFloat(byte[] bytes, int offset, int size) Returns a float value from array of bytes.
static byte[]	calculateCRC(byte[] data, int offset, int len) Calculates and returns the CRC using the data passed in parameters.
static boolean	checkCRC(byte[] data, int offset, int len, byte[] crc) Checks the CRC and returns true if it is correct, otherwise false.
static void	DEBUG(java.lang.String className, java.lang.String method, java.lang.String msg)
static java.io.BufferedReader	fileParser(java.lang.String path, java.lang.String fileName) Method to use to access a file in your resources folder...
static java.lang.String	getHexString(byte[] b) Utility method to convert a byte array in a string made up of hex (0,.. 9, a,..f).
static java.lang.String	getHexString(byte[] b, int offset, int length) Utility method to convert a byte array in a string made up of hex (0,.. 9, a,..f)
static java.lang.String	getStringRndVal(int factor) Retrieves a random value rounded to 2 decimal...
static java.lang.String	md5sum(java.lang.String msg) Returns the md5 of any input...
static byte[]	readBytes(java.io.InputStream in) Reads the incoming data from an input stream as long as there is something to read and saved the data in an array of bytes.
static byte[]	readLine(java.io.InputStream in) Reads a line of text.
static byte[]	readNBytes(java.io.InputStream in, int len) Reads from the given input stream an amount of bytes and retrieves these data as an array of bytes.
static void	sendBytes(java.io.OutputStream out, byte[] toSend, int offset, int length) This method sends the content of the buffer to the given OutputStream.
static int	unsignedByteToSignedInt(byte from) Converts an unsigned byte to a signed integer.
static void	waitSomeTime(int ms) To wait some times ...
static void	writeLine(java.io.OutputStream out, byte[] toSend) Send the data contained in the given array of bytes through the output stream.

Methods inherited from class java.lang.Object

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

Field Detail

TCP_BUFFER_SIZE

public static final int TCP_BUFFER_SIZE

Default size for the TCP input stream

See Also:

Constant Field Values

rnd

public static java.util.Random rnd

Object to get some random values...

Constructor Detail

Utility

public Utility()

Method Detail

calculateCRC

public static byte[] calculateCRC(byte[] data,
                                  int offset,
                                  int len)

Calculates and returns the CRC using the data passed in parameters.

Parameters:

data - a byte array containing the data to send

offset - the offset

len - the data length

Returns:

byte[] the CRC

checkCRC

public static boolean checkCRC(byte[] data,
                               int offset,
                               int len,
                               byte[] crc)

Checks the CRC and returns true if it is correct, otherwise false.

Parameters:

data - a byte array containing the data to send

offset - the offset

len - the data length

crc - a byte array containing the CRC to check

Returns:

boolean true if the CRC is correct, otherwise false

unsignedByteToSignedInt

public static int unsignedByteToSignedInt(byte from)

Converts an unsigned byte to a signed integer.

Parameters:

from - an unsigned byte to convert to a signed integer

Returns:

int a signed integer

getHexString

public static java.lang.String getHexString(byte[] b)

Utility method to convert a byte array in a string made up of hex (0,.. 9, a,..f). The array of bytes is converted from offset 0 to its end.

Parameters:

b - Array of bytes to be converted in HEX string.

Returns:

A String representing the HEX values of the given array of bytes.

getHexString

public static java.lang.String getHexString(byte[] b,
                                            int offset,
                                            int length)

Utility method to convert a byte array in a string made up of hex (0,.. 9, a,..f)

Parameters:

b - The byte array to convert in HEX string

offset - The index where we start to convert from.

length - The amount of bytes to convert in HEX string

Returns:

A String representing the HEX values of the selected bytes of the array.

getStringRndVal

public static java.lang.String getStringRndVal(int factor)

Retrieves a random value rounded to 2 decimal...

Parameters:

factor - A coefficient which the random value is multiplied with.

Returns:

A random value rounded to 2 decimal converted to a String.

readBytes

public static byte[] readBytes(java.io.InputStream in)
                        throws java.io.IOException

Reads the incoming data from an input stream as long as there is something to read and saved the data in an array of bytes. The method is blocking ! This method blocks until input data is available, end of file is detected, or an exception is thrown. If the length of of read data is zero, then no bytes are read and an empty array of bytes is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at the end of the file, the value -1 is returned; otherwise, at least one byte is read and returned as an array of bytes.

Parameters:

in - The input Stream where to read the data coming from.

Returns:

The read data as an array of bytes. Or null if the has been closed by the peer while waiting for incoming data.

Throws:

java.io.IOException - If the first byte cannot be read for any reason other than the end of the file, if the input stream has been closed, or if some other I/O error occurs.

readNBytes

public static byte[] readNBytes(java.io.InputStream in,
                                int len)
                         throws java.io.IOException

Reads from the given input stream an amount of bytes and retrieves these data as an array of bytes. The method is blocking !

Parameters:

in - The input stream where to read the data coming from.

len - The amount of data to read

Returns:

The read data as an array of bytes.

Throws:

java.io.IOException - If the first byte cannot be read for any reason other than the end of the file, if the input stream has been closed, or if some other I/O error occurs.

readLine

public static byte[] readLine(java.io.InputStream in)
                       throws java.io.IOException

Reads a line of text. A line is considered to be terminated by any one of a line feed ('\n'), a carriage return ('\r'), or a carriage return followed immediately by a line feed.

Parameters:

in - The Input Stream to read from.

Returns:

An array of bytes containing the contents of the line, not including any line-termination characters, or null if the end of the stream has been reached.

Throws:

java.io.IOException - If an I/O error occurs

writeLine

public static void writeLine(java.io.OutputStream out,
                             byte[] toSend)
                      throws java.io.IOException

Send the data contained in the given array of bytes through the output stream. If the data to send do not end with a carriage return, the method adds '\r\n' at the end.

Parameters:

out - The Output Stream to send the data to.

toSend - The data to send

Throws:

java.io.IOException - If an I/O error occurs

sendBytes

public static void sendBytes(java.io.OutputStream out,
                             byte[] toSend,
                             int offset,
                             int length)
                      throws java.io.IOException

This method sends the content of the buffer to the given OutputStream. This content is specified by the starting position, defined by offset, and the amount of bytes,defined by length. If an error occurs during this process, a exception will be raised.

Parameters:

out - The Output Stream to send the data to.

toSend - The data to send

offset - The starting position in the buffer of data

length - The amount of bytes to be sent.

Throws:

java.io.IOException - If an I/O error occurs

waitSomeTime

public static void waitSomeTime(int ms)

To wait some times ... Simply give the delay you want to wait for and that's it !

Parameters:

ms - The amount of time to wait expressed in milli-seconds [ms].

md5sum

public static java.lang.String md5sum(java.lang.String msg)

Returns the md5 of any input...

Parameters:

msg - The input string to process

Returns:

The md5 of the input string.

bytesToFloat

public static java.lang.Float bytesToFloat(byte[] bytes,
                                           int offset,
                                           int size)

Returns a float value from array of bytes. This byte's array can only be 2 or 4 bytes long.

Parameters:

bytes - The array of bytes to convert.

offset - The position where the method has to start to get the bytes from.

size - The amount of bytes to convert.

Returns:

A Float value or null if the process failed.

fileParser

public static java.io.BufferedReader fileParser(java.lang.String path,
                                                java.lang.String fileName)

Method to use to access a file in your resources folder... The file you want to access has to be under the `resources` folder of your project. You can create as many sub-folders as you want, they will become the path of the file to work with. This path is given to the method by the parameter `path` and the file is identified by its name and extension.

Parameters:

path - folder's hierarchy (if exists) from `resources`

fileName - Name of the file to access

Returns:

A BufferedReader related to the file you want to work with, or null if the file could not be reached.

DEBUG

public static void DEBUG(java.lang.String className,
                         java.lang.String method,
                         java.lang.String msg)