org.ka2ddo.ax25

Class AX25Message

java.lang.Object

org.ka2ddo.ax25.AX25Message

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.lang.Comparable<AX25Message>

Direct Known Subclasses:

Message, OpenTracMessage

public abstract class AX25Message
extends java.lang.Object
implements java.lang.Comparable<AX25Message>, java.io.Serializable, java.lang.Cloneable

This class defines the common infrastructure for one decoded AX.25 message. Subclasses implement the details for different layer 3 and above protocols.

Author:

Andrew Pavlin, KA2DDO

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AX25Message.Precedence This enum defines the allowed traffic precedence levels for messages.

Field Summary

Fields

Modifier and Type	Field and Description
protected static java.util.Set<ProtocolFamily>	APRS_AND_OPENTRAC A read-only protocol set that includes both APRS and OpenTRAC.
AX25Frame	ax25Frame The AX.25 frame object from which this Message was extracted.
protected java.util.Map<java.lang.Enum,java.lang.Object>	extensions Optional map of extracted data fields in this APRS message.
protected boolean	invalid Indicates whether message was correctly formatted or otherwise parseable.
java.lang.String	originatingCallsign Callsign of the station originating this message.
java.lang.String	originatingDest Destination "callsign" from the station originating this message.
static long	PERMANENT Reserved constant for non-expiring objects' timestamp.
long	rcptTime The time the message was received by the system in Java standard milliseconds since 1970 UTC.
java.lang.String	thirdParty The entire third-party routing path for this AX25Message, or null if this AX25message is still on its original network.
long	timestamp Message timestamp in Java standard milliseconds since 1970 UTC.
static java.util.TimeZone	UTC TimeZone object for Greenwich Mean Time (or Universal Coordinated Time), used for converting text string times and dates into binary.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AX25Message() Constructor for partially initialized AX25Message.
protected	AX25Message(java.lang.String thirdParty, long rcptTime) Constructor for AX25Message specifying the third-party network routing and receive time of the message.

Method Summary

Modifier and Type	Method and Description
protected abstract boolean	bodyEquals(AX25Message other) Compare the contents of the body of the message, reporting if they match.
int	compareTo(AX25Message o) Compares this object with the specified object for order.
AX25Message	dup() Creates and returns a copy of this AX25Message.
boolean	equals(java.lang.Object o) Test if the Object o is a duplicate of this Message.
void	extractSource() Extract the originating station callsign for this AX25Message.
AX25Frame	getAx25Frame() Get the AX.25 frame from which this Message was extracted.
java.lang.Object	getExtension(java.lang.Enum key) Get a particular extension value from this message.
java.lang.String	getFirstDigipeat(AX25Callsign[] digipeaters) Return the callsign of the first digipeat station for this message.
java.lang.String	getLastDigipeat(AX25Callsign[] digipeaters) Return the callsign of the last digipeat station for this message.
java.lang.String	getNthDigipeat(AX25Callsign[] digipeaters, int index) Return the callsign of the Nth digipeat station for this message.
static java.lang.String	getOriginalDestination(AX25Callsign dest, java.lang.String thirdParty) Extract the callsign of the original destination of this message.
static java.lang.String	getOriginalSource(AX25Callsign src, java.lang.String thirdParty) Extract the callsign of the original destination of this message.
java.lang.String	getOriginatingCallsign() Get the callsign of the station that originated this message (not of any Tx-Igate relay).
java.lang.String	getOriginatingDest() Get the destination address oeiginally specified bv the station that originated this message.
AX25Message.Precedence	getPrecedence() Report the traffic-handling precedence for this message instance.
java.util.Set<ProtocolFamily>	getProtocols() Get the protocol family or families that this message corresponds to, so ports that don't support all protocols will not forward inappropriate packets.
long	getRcptTime() Get the timestamp this AX25Message was received in milliseconds since 1 Jan 1970 UTC.
java.util.Map<java.lang.Enum,java.lang.Object>	getReadOnlyExtensionMap() Get a reference to the extension map that should not be modified.
long	getTimestamp() Get the timestamp associated with this Message in milliseconds since 1 Jan 1970 UTC.
int	hashCode() Returns a hash code for this Message.
boolean	hasPosition() Report if this AX25Message contains position data.
boolean	hasThisFirstDigi(AX25Callsign[] digipeaters, java.lang.String digiCallsign) Test if the specified callsign is the first digipeat station for this message.
abstract boolean	hasWeather() Report if this AX25Message contains weather information.
static int	indexOf(byte[] buf, int bufLen, char matchCh, int startPos) Search a byte array (assumed to be an ASCII string) for a matching character.
static int	indexOf(byte[] buf, int bufLen, java.lang.String matchStr, int startPos) Search a byte array (assumed to be an ASCII string) for a matching ASCII string.
boolean	isDirect() Test if this message was sent directly (without any relay station).
boolean	isInvalid() Test if this message was flagged as invalid.
java.lang.Boolean	isRf(int maxDigis) Test if this AX25Message came from an RF connection.
static boolean	onlyDigits(byte[] body, int pos, int len) Test if the specified part of the message body is strictly only ASCII digits.
static boolean	onlyDigits(java.lang.String body, int pos, int len) Test if the specified part of the message body is strictly only ASCII digits.
static boolean	onlyDigitsOrMinus(byte[] body, int pos, int len) Test if the specified part of the message body is strictly only ASCII digits.
static boolean	onlyDigitsOrPeriod(java.lang.String body, int pos, int len) Test if the specified part of the message body is strictly only ASCII digits.
protected static boolean	onlyDigitsOrSpace(byte[] body, int pos, int len) Test if the specified part of the message body is strictly only ASCII digits or space characters.
protected static boolean	onlyDigitsPlus(byte[] body, int pos, int len) Test if the specified part of the message body is only ASCII digits or characters just after the digits (to support base+offset message codes in APRS).
protected static boolean	onlyPeriods(byte[] body, int pos, int len) Test if the specified part of the message body is strictly only period characters.
java.lang.String	paramString() Descriptive text about this message, to be included in the toString() method's response.
void	setAx25Frame(AX25Frame ax25Frame) Attach the AX.25 frame from which this Message was extracted.
void	setInvalid(boolean invalid) Mark if this message is invalid or not.
void	setOriginatingCallsign(java.lang.String originatingCallsign) Set the originating callsign for this AX25Message.
void	setRcptTime(long rcptTime) Change the receive time of this message.
void	setTimestamp(long timestamp) Change the timestamp of this message.
static java.lang.String[]	split(java.lang.String line, char separator) This is a more optimized version of String.split() that doesn't require compiling and evaluating regular expression patterns to do it, thereby saving chunks of transient heap (and probably some CPU time as well).
<K extends java.lang.Enum,V> void	storeExtension(K key, V value) Store an extracted data element in the Message.
java.lang.String	toString() Returns a string representation of the object.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

PERMANENT

public static final long PERMANENT

Reserved constant for non-expiring objects' timestamp.

See Also:

Constant Field Values

ax25Frame

public AX25Frame ax25Frame

The AX.25 frame object from which this Message was extracted.

originatingCallsign

public java.lang.String originatingCallsign

Callsign of the station originating this message. This may not match the sender callsign if the message was relayed through a third-party network (such as APRS-IS). In such cases, sender will be the callsign of the station transmitting the message onto RF, and originatingCallsign will be taken from the third-party routing information to indicate the station that originally injected this message into the network of networks.

See Also:

AX25Frame.sender

originatingDest

public java.lang.String originatingDest

Destination "callsign" from the station originating this message. This may not match the destination callsign if the message was relayed through a third-party network (such as APRS-IS). In such cases, destination will be the "tocall" (assuming APRS) of the station transmitting the message onto RF, and originatingDest will be taken from the third-party routing information to indicate the destination that originally injected this message into the network of networks.

Since:

PROVIDER_API_VERSION == 35

See Also:

AX25Frame.dest

thirdParty

public java.lang.String thirdParty

The entire third-party routing path for this AX25Message, or null if this AX25message is still on its original network.

timestamp

public long timestamp

Message timestamp in Java standard milliseconds since 1970 UTC. May be different from rcptTime if the message body has a time value in it.

rcptTime

public long rcptTime

The time the message was received by the system in Java standard milliseconds since 1970 UTC.

invalid

protected boolean invalid

Indicates whether message was correctly formatted or otherwise parseable.

extensions

protected java.util.Map<java.lang.Enum,java.lang.Object> extensions

Optional map of extracted data fields in this APRS message. May be null if no extensions present in the message.

UTC

public static final java.util.TimeZone UTC

TimeZone object for Greenwich Mean Time (or Universal Coordinated Time), used for converting text string times and dates into binary.

APRS_AND_OPENTRAC

protected static final java.util.Set<ProtocolFamily> APRS_AND_OPENTRAC

A read-only protocol set that includes both APRS and OpenTRAC.

See Also:

getProtocols()

Constructor Detail

AX25Message

protected AX25Message()

Constructor for partially initialized AX25Message.

AX25Message

protected AX25Message(java.lang.String thirdParty,
                      long rcptTime)

Constructor for AX25Message specifying the third-party network routing and receive time of the message.

Parameters:

thirdParty - The entire third-party routing path for this AX25Message, or null if this AX25message is still on its original network.

rcptTime - The time the message was received by the system in Java standard milliseconds since 1970 UTC.

Method Detail

equals

public boolean equals(java.lang.Object o)

Test if the Object o is a duplicate of this Message.

Overrides:

equals in class java.lang.Object

Parameters:

o - Object to compare against this message.

Returns:

true if o is a Message with the same contents as this Message

bodyEquals

protected abstract boolean bodyEquals(AX25Message other)

Compare the contents of the body of the message, reporting if they match. This method must be overridden by concrete subclasses, but will only be called when the Class of the other message equals the Class of this message.

Parameters:

other - another AX25Message to compare against

Returns:

boolean true if the body values are equivalent

hashCode

public int hashCode()

Returns a hash code for this Message.

Overrides:

hashCode in class java.lang.Object

Returns:

a hash code value for this object.

compareTo

public int compareTo(AX25Message o)

Compares this object with the specified object for order. Returns a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

Specified by:

compareTo in interface java.lang.Comparable<AX25Message>

Parameters:

o - the object to be compared.

Returns:

a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

Throws:

java.lang.ClassCastException - if the specified object's type prevents it from being compared to this object.

onlyDigits

public static boolean onlyDigits(java.lang.String body,
                                 int pos,
                                 int len)

Test if the specified part of the message body is strictly only ASCII digits.

Parameters:

body - String containing the message body

pos - starting index in the array to test

len - number of bytes to test

Returns:

boolean true if all the bytes are ASCII digits

onlyDigitsOrPeriod

public static boolean onlyDigitsOrPeriod(java.lang.String body,
                                         int pos,
                                         int len)

Test if the specified part of the message body is strictly only ASCII digits.

Parameters:

body - String containing the message body

pos - starting index in the array to test

len - number of bytes to test

Returns:

boolean true if all the bytes are ASCII digits

onlyDigits

public static boolean onlyDigits(byte[] body,
                                 int pos,
                                 int len)

Test if the specified part of the message body is strictly only ASCII digits.

Parameters:

body - byte array containing the message body

pos - starting index in the array to test

len - number of bytes to test

Returns:

boolean true if all the bytes are ASCII digits

onlyDigitsOrMinus

public static boolean onlyDigitsOrMinus(byte[] body,
                                        int pos,
                                        int len)

Test if the specified part of the message body is strictly only ASCII digits.

Parameters:

body - byte array containing the message body

pos - starting index in the array to test

len - number of bytes to test

Returns:

boolean true if all the bytes are ASCII digits

onlyDigitsPlus

protected static boolean onlyDigitsPlus(byte[] body,
                                        int pos,
                                        int len)

Test if the specified part of the message body is only ASCII digits or characters just after the digits (to support base+offset message codes in APRS).

Parameters:

body - byte array containing the message body

pos - starting index in the array to test

len - number of bytes to test

Returns:

boolean true if all the bytes are in the 16-byte block containing ASCII digits

onlyDigitsOrSpace

protected static boolean onlyDigitsOrSpace(byte[] body,
                                           int pos,
                                           int len)

Test if the specified part of the message body is strictly only ASCII digits or space characters.

Parameters:

body - byte array containing the message body

pos - starting index in the array to test

len - number of bytes to test

Returns:

boolean true if all the bytes are ASCII digits or spaces

onlyPeriods

protected static boolean onlyPeriods(byte[] body,
                                     int pos,
                                     int len)

Test if the specified part of the message body is strictly only period characters.

Parameters:

body - byte array containing the message body

pos - starting index in the array to test

len - number of bytes to test

Returns:

boolean true if all the bytes are periods

indexOf

public static int indexOf(byte[] buf,
                          int bufLen,
                          char matchCh,
                          int startPos)

Search a byte array (assumed to be an ASCII string) for a matching character.

Parameters:

buf - byte array to search

bufLen - index of end of used part of buffer

matchCh - character value to search for in a forward search

startPos - zero-based index to start searching at

Returns:

first index of character occurrence after the start pos, or -1 if not found

indexOf

public static int indexOf(byte[] buf,
                          int bufLen,
                          java.lang.String matchStr,
                          int startPos)

Search a byte array (assumed to be an ASCII string) for a matching ASCII string.

Parameters:

buf - byte array to search

bufLen - index of end of used part of buffer

matchStr - String value to search for in a forward search

startPos - zero-based index to start searching at

Returns:

first index of string occurrence after the start pos, or -1 if not found

paramString

public java.lang.String paramString()

Descriptive text about this message, to be included in the toString() method's response. This method may be overridden. Its default implementation returns an empty string.

Returns:

String describing the contents of this message

See Also:

toString()

toString

public java.lang.String toString()

Returns a string representation of the object.

Overrides:

toString in class java.lang.Object

Returns:

a string representation of the object.

extractSource

public void extractSource()
                   throws java.lang.IllegalArgumentException

Extract the originating station callsign for this AX25Message.

Throws:

java.lang.IllegalArgumentException - if thirdParty string is provided but doesn't have a sender>dest delimiter

getAx25Frame

public final AX25Frame getAx25Frame()

Get the AX.25 frame from which this Message was extracted.

Returns:

transport-compatible AX25Frame for this Message

setAx25Frame

public final void setAx25Frame(AX25Frame ax25Frame)

Attach the AX.25 frame from which this Message was extracted.

Parameters:

ax25Frame - AX25Frame object containing the encoding of this Message

getOriginalSource

public static java.lang.String getOriginalSource(AX25Callsign src,
                                                 java.lang.String thirdParty)

Extract the callsign of the original destination of this message.

Parameters:

src - AX25Callsign of the source of the original AX25Frame

thirdParty - String of the third-party routing of this message, or null if not routed over another network

Returns:

source callsign String

getOriginalDestination

public static java.lang.String getOriginalDestination(AX25Callsign dest,
                                                      java.lang.String thirdParty)

Extract the callsign of the original destination of this message.

Parameters:

dest - AX25Callsign of the destination (tocall) of the original AX25Frame

thirdParty - String of the third-party routing of this message, or null if not routed over another network

Returns:

destination callsign String

getLastDigipeat

public java.lang.String getLastDigipeat(AX25Callsign[] digipeaters)

Return the callsign of the last digipeat station for this message.

Parameters:

digipeaters - array of AX25Callsign digipeater addresses in AX.25 frame

Returns:

String station ID of last digipeat station, or empty string if received directly from originating station

getFirstDigipeat

public java.lang.String getFirstDigipeat(AX25Callsign[] digipeaters)

Return the callsign of the first digipeat station for this message. Note this code considers a direct receive by an I-gate as the I-gate being the first "digipeater".

Parameters:

digipeaters - array of AX25Callsign digipeater addresses in AX.25 frame

Returns:

String station ID of first digipeat station, or empty string if received directly from originating station

getNthDigipeat

public java.lang.String getNthDigipeat(AX25Callsign[] digipeaters,
                                       int index)

Return the callsign of the Nth digipeat station for this message. Note this code considers a direct receive by an I-gate as the I-gate being the first "digipeater". If the index is past all the third-party digipeaters and I-gate and this is an RF packet, the RF digipeaters used by the transmitting I-gate will then be iterated through. Note that RF digipeater aliases that are not marked has-been-repeated will not be counted, nor will "q" codes in a third-party prefix.

Parameters:

digipeaters - array of AX25Callsign digipeater addresses in AX.25 frame

index - zero-based index into the list of digipeat aliases

Returns:

String station ID of Nth digipeat station, or null if past end of used digipeat list

hasThisFirstDigi

public boolean hasThisFirstDigi(AX25Callsign[] digipeaters,
                                java.lang.String digiCallsign)

Test if the specified callsign is the first digipeat station for this message.

Parameters:

digipeaters - array of AX25Callsign digipeater addresses in AX.25 frame

digiCallsign - String callsign/SSID of digipeater

Returns:

boolean true if the specified digipeater is the first digi for this message

getTimestamp

public long getTimestamp()

Get the timestamp associated with this Message in milliseconds since 1 Jan 1970 UTC.

Returns:

time message was received or the timestamp in the message, or -1 if this is a permanent (non-timing-out message)

hasWeather

public abstract boolean hasWeather()

Report if this AX25Message contains weather information.

Returns:

boolean true if weather information in this AX25Message

hasPosition

public boolean hasPosition()

Report if this AX25Message contains position data. The default implementation returns false; position-reporting subclasses are expected to override this.

Returns:

boolean true if message contains position information

setTimestamp

public void setTimestamp(long timestamp)

Change the timestamp of this message. Intended only for use by the Transmitter class when creating a time-stamped duplicate of a periodically-repeated APRS Message.

Parameters:

timestamp - new time in Java milliseconds since epoch

setOriginatingCallsign

public void setOriginatingCallsign(java.lang.String originatingCallsign)

Set the originating callsign for this AX25Message. This should only be called on SendableMessages to initialize them before transmission.

Parameters:

originatingCallsign - String of the originating station callsign of this message

getOriginatingCallsign

public java.lang.String getOriginatingCallsign()

Get the callsign of the station that originated this message (not of any Tx-Igate relay).

Returns:

String callsign

getOriginatingDest

public java.lang.String getOriginatingDest()

Get the destination address oeiginally specified bv the station that originated this message.

Returns:

String callsign

getRcptTime

public long getRcptTime()

Get the timestamp this AX25Message was received in milliseconds since 1 Jan 1970 UTC.

Returns:

time message was received

setRcptTime

public void setRcptTime(long rcptTime)

Change the receive time of this message. Intended only for use by the Transmitter class when creating a time-stamped duplicate of a periodically-repeated APRS Message.

Parameters:

rcptTime - new time in Java milliseconds since epoch

isInvalid

public boolean isInvalid()

Test if this message was flagged as invalid.

Returns:

boolean true if this message is marked as invalid

setInvalid

public void setInvalid(boolean invalid)

Mark if this message is invalid or not.

Parameters:

invalid - boolean true if message should be considered invalid or incorrect syntax

getPrecedence

public AX25Message.Precedence getPrecedence()

Report the traffic-handling precedence for this message instance. Expected to be overridden by subclasses that have precedence fields.

Returns:

Precedence level for this AX25Message

dup

public AX25Message dup()

Creates and returns a copy of this AX25Message.

Returns:

a clone of this instance.

See Also:

Cloneable

storeExtension

public <K extends java.lang.Enum,V> void storeExtension(K key,
                                                        V value)

Store an extracted data element in the Message.

Type Parameters:

K - any enum subclass

V - any Java object class

Parameters:

key - Enum that identifies the particular data item

value - the data value

See Also:

DataExtensionEnum, WeatherEnum

getReadOnlyExtensionMap

public java.util.Map<java.lang.Enum,java.lang.Object> getReadOnlyExtensionMap()

Get a reference to the extension map that should not be modified.

Returns:

Map of extension data element (may be an empty Map)

See Also:

DataExtensionEnum, WeatherEnum

getExtension

public java.lang.Object getExtension(java.lang.Enum key)

Get a particular extension value from this message.

Parameters:

key - Enum instance identifying the desired extension

Returns:

value for that extension, or null if no value stored

See Also:

DataExtensionEnum, WeatherEnum

getProtocols

public java.util.Set<ProtocolFamily> getProtocols()

Get the protocol family or families that this message corresponds to, so ports that don't support all protocols will not forward inappropriate packets.

Returns:

array of supported ProtocolFamily enums

isRf

public java.lang.Boolean isRf(int maxDigis)

Test if this AX25Message came from an RF connection.

Parameters:

maxDigis - int maximum number of digipeat hops before we're not going to count it

Returns:

Boolean.TRUE if a local Rf transmission, Boolean.FALSE if not RF-only, null if we can't tell

isDirect

public boolean isDirect()

Test if this message was sent directly (without any relay station).

Returns:

boolean true if direct, false if not

split

public static java.lang.String[] split(java.lang.String line,
                                       char separator)

This is a more optimized version of String.split() that doesn't require compiling and evaluating regular expression patterns to do it, thereby saving chunks of transient heap (and probably some CPU time as well).

Parameters:

line - the String to split at occurrences of the separator

separator - the String delimiting substrings of the line

Returns:

array of Strings split at the various points the separator appears