net.sf.marineapi.nmea.sentence

Class Checksum

java.lang.Object

net.sf.marineapi.nmea.sentence.Checksum

public final class Checksum
extends Object

Provides Sentence checksum calculation and utilities.

Author:

Kimmo Tuukkanen

Method Summary

Modifier and Type	Method and Description
static String	add(String nmea) Append or replace existing checksum in specified NMEA sentence.
static String	calculate(String nmea) Calculates checksum for given NMEA sentence, i.e.
static int	index(String nmea) Returns the index of checksum separator char in specified NMEA sentence.
static String	xor(String str) Calculates XOR checksum of given String.

Methods inherited from class java.lang.Object

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

Method Detail

add

public static String add(String nmea)

Append or replace existing checksum in specified NMEA sentence.

Parameters:

nmea - Sentence in String representation

Returns:

The specified String with checksum added.

calculate

public static String calculate(String nmea)

Calculates checksum for given NMEA sentence, i.e. XOR of each character between '$' and '*' characters (exclusive).

Parameters:

nmea - Sentence String with or without checksum.

Returns:

Hexadecimal checksum

xor

public static String xor(String str)

Calculates XOR checksum of given String. Resulting hex value is returned as a String in two digit format, padded with a leading zero if necessary.

Parameters:

str - String to calculate checksum for.

Returns:

Hexadecimal checksum

index

public static int index(String nmea)

Returns the index of checksum separator char in specified NMEA sentence. If separator is not found, returns the String length.

Parameters:

nmea - Sentence String

Returns:

Index of checksum separator or String length.