Message

java.lang.Object
- org.ka2ddo.ax25.AX25Message
- - org.ka2ddo.aprs.Message

All Implemented Interfaces:

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

Direct Known Subclasses:

DefaultMessage, MessageMessage, PositionlessWeatherReport, PositionMessage, Query, StationCapabilities, StatusMessage, TelemetryMessage, UltimeterRawMessage
```
public abstract class Message
extends AX25Message
implements CommentedMessage
```
This abstract class defines the common parts of one APRS message. Subclasses handle the details of specific message types.

Author:

Andrew Pavlin, KA2DDO

See Also:

Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from class org.ka2ddo.ax25.AX25Message
  AX25Message.Precedence

Field Summary

Fields
Modifier and Type	Field and Description
`protected static boolean`	`appendCR` Flag for APRS message generators as to whether a trailing carriage return (CR or \\r character) should be appended to APRS packets.
`protected static java.util.Set<ProtocolFamily>`	`APRS_AND_OPENTRAC_AND_RAW` ProtocolFamily set providing all protocols.
`protected static java.util.Set<ProtocolFamily>`	`APRS_AND_RAW` Set of ProtocolFamily values for both APRS and raw AX.25.
`protected java.lang.String`	`comment` Free-text comment in this message.
`protected byte`	`msgType` APRS message type code (prefix character in the message text).
`static java.lang.String`	`S_PERMANENT` Reserved APRS timestamp string for permanent Objects.
`static java.lang.String`	`S_PERMANENT_UC` Reserved APRS timestamp string for permanent Objects, with uppercase timezone letter.
`protected char`	`symbolCode` The APRS symbol code within the specified table for the station originating this message.
`protected char`	`symTableId` The APRS symbol table ID (or overlay character) for the station originating this message.

Fields inherited from class org.ka2ddo.ax25.AX25Message
APRS_AND_OPENTRAC, ax25Frame, extensions, invalid, originatingCallsign, originatingDest, PERMANENT, rcptTime, thirdParty, timestamp, UTC

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`Message()` Create an uninitialized message.
`protected`	`Message(byte msgType, java.lang.String thirdParty, long rcptTime)` Set up this superclass's infrastructure for a particular message type at a particular receive time with the specified third-party routing.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`bodyEquals(AX25Message o)` 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.
`protected int`	`decodeDatestamp(byte[] body, int pos)` Extract an APRS-standard 8-digit date/timestamp from a byte array presumably containing a timestamped APRS message and store it in the timestamp field of this Message object.
`protected int`	`decodeHurricaneParams(byte[] body, int offset)` Extract APRS-standard hurricane/tropical storm information from a message body.
`protected int`	`decodeTimestamp(byte[] body, int pos, long rcvTimestamp)` Extract an APRS-standard 6-digit timestamp from a byte array presumably containing a timestamped APRS message and store it in the timestamp field of this Message object.
`protected int`	`decodeWeatherParams(byte[] body, int offset)` Extract APRS-standard weather information from a message body.
`protected int`	`decodeWeatherParams(java.lang.String body, int offset)` Extract APRS-standard weather information from a message body.
`AX25Message`	`dup()` Creates and returns a deep copy of this Message.
`protected static java.lang.String`	`encodeTimestamp(java.util.Date date, long now)` Produce a APRS-standard 6-digit timestamp string for the specified date/time, using the most precise format possible relative to the current time.
`protected void`	`extractComment(byte[] body, int offset)` Extract the remaining text in the byte buffer as the free-text comment of this message.
`protected void`	`extractComment(byte[] body, int startPos, int endPos)` Extract the remaining text in the byte buffer as the free-text comment of this message.
`static java.lang.String`	`extractSymbol(java.lang.String dest)` Decode a symbol from the destination tocall (handling the case of old hardware and/or software whose limited message set does not include messages with symbol codes in the message body).
`static java.lang.String`	`formatBody(byte[] body, int offset)` Convert a byte array into a UTF_8 printable string.
`java.lang.String`	`getComment()` Get the free-text comment of this message,
`java.lang.String`	`getExtensionString()` Build a formatted string of the weather data known to this message,
`int`	`getMsgType()` Get the APRS message type code for 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.
`char`	`getSymbolCode()` Get the APRS symbol code for this Message.
`char`	`getSymTableId()` Get the APRS symbol table ID or overlay character for this Message.
`boolean`	`hasWeather()` Report if this Message contains weather information.
`protected void`	`inferSymbol(AX25Callsign src, AX25Callsign dst)` Decode a symbol from the destination AX25Callsign (handling the case of old hardware and/or software whose limited message set does not include messages with symbol codes in the message body).
`static boolean`	`isAppendCR()` Indicate whether trailing CR should be appended to generated APRS packets.
`boolean`	`isSymbolInferred()` Report whether the non-null APRS symbol reported by this message is explicit or inferred from destination or source callsign.
`protected static boolean`	`looksLikeLongFormatLatitude(byte[] body, int pos, int len)` Test the byte array to see if it looks like it contains a APRS text-format (long) position indicator.
`java.lang.String`	`paramString()` Descriptive text about this message, to be included in the toString() method's response.
`static void`	`setAppendCR(boolean appendCR)` Specify whether trailing CR should be appended to generated APRS packets.
`void`	`setComment(java.lang.String comment)` Set the free-text comment for this Message.
`void`	`setSymbolCode(char symbolCode)` Set the APRS symbol code for this Message.
`void`	`setSymTableId(char symTableId)` Set the APRS symbol table ID or overlay character for this 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
  - S_PERMANENT
```
public static final java.lang.String S_PERMANENT
```
    Reserved APRS timestamp string for permanent Objects.
    
    See Also:
    
    Constant Field Values
  - S_PERMANENT_UC
```
public static final java.lang.String S_PERMANENT_UC
```
    Reserved APRS timestamp string for permanent Objects, with uppercase timezone letter.
    
    See Also:
    
    Constant Field Values
  - APRS_AND_OPENTRAC_AND_RAW
```
protected static final java.util.Set<ProtocolFamily> APRS_AND_OPENTRAC_AND_RAW
```
    ProtocolFamily set providing all protocols.
  - appendCR
```
protected static boolean appendCR
```
    Flag for APRS message generators as to whether a trailing carriage return (CR or \\r character) should be appended to APRS packets.
  - symTableId
```
protected char symTableId
```
    The APRS symbol table ID (or overlay character) for the station originating this message. May be zero if no symbol defined by this message.
    
    See Also:
    
    symbolCode
  - symbolCode
```
protected char symbolCode
```
    The APRS symbol code within the specified table for the station originating this message. May be zero if no symbol defined by this message.
    
    See Also:
    
    symTableId
  - comment
```
protected java.lang.String comment
```
    Free-text comment in this message.
  - msgType
```
protected byte msgType
```
    APRS message type code (prefix character in the message text).
  - APRS_AND_RAW
```
protected static final java.util.Set<ProtocolFamily> APRS_AND_RAW
```
    Set of ProtocolFamily values for both APRS and raw AX.25.
- Constructor Detail
  - Message
```
protected Message()
```
    Create an uninitialized message.
  - Message
```
protected Message(byte msgType,
                  java.lang.String thirdParty,
                  long rcptTime)
```
    Set up this superclass's infrastructure for a particular message type at a particular receive time with the specified third-party routing.
    
    Parameters:
    
    msgType - printable ASCII character identifying the APRS message type
    
    thirdParty - String of third-party network routing data (may be null)
    
    rcptTime - time in milliseconds since Jan 1 1970 UTC that message was received or created
- Method Detail
  - bodyEquals
```
public boolean bodyEquals(AX25Message o)
```
    Compare the contents of the body of the message, reporting if they match.
    
    Specified by:
    
    bodyEquals in class AX25Message
    
    Parameters:
    
    o - another AX25Message to compare against
    
    Returns:
    
    boolean true if the body values are equivalent
  - 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>
    
    Overrides:
    
    compareTo in class 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.
  - toString
```
public java.lang.String toString()
```
    Returns a string representation of the object.
    
    Overrides:
    
    toString in class AX25Message
    
    Returns:
    
    a string representation of the object.
  - getMsgType
```
public int getMsgType()
```
    Get the APRS message type code for this message.
    
    Returns:
    
    the ASCII character identifying the type of this APRS message
  - decodeTimestamp
```
protected int decodeTimestamp(byte[] body,
                              int pos,
                              long rcvTimestamp)
```
    Extract an APRS-standard 6-digit timestamp from a byte array presumably containing a timestamped APRS message and store it in the timestamp field of this Message object.
    
    Parameters:
    
    body - byte array containing the message
    
    pos - index into the array where the timestamp is supposed to start
    
    rcvTimestamp - default time (in Java milliseconds since Jan 1 1970 UTC) to use if timestamp field is all period characters
    
    Returns:
    
    index into the byte array immediately following the decoded timestamp
    
    See Also:
    
    AX25Message.timestamp
  - decodeDatestamp
```
protected int decodeDatestamp(byte[] body,
                              int pos)
```
    Extract an APRS-standard 8-digit date/timestamp from a byte array presumably containing a timestamped APRS message and store it in the timestamp field of this Message object.
    
    Parameters:
    
    body - byte array containing the message
    
    pos - index into the array where the timestamp is supposed to start
    
    Returns:
    
    index into the byte array immediately following the decoded timestamp
    
    See Also:
    
    AX25Message.timestamp
  - encodeTimestamp
```
protected static java.lang.String encodeTimestamp(java.util.Date date,
                                                  long now)
```
    Produce a APRS-standard 6-digit timestamp string for the specified date/time, using the most precise format possible relative to the current time.
    
    Parameters:
    
    date - Data object of the time to format
    
    now - current time in Java milliseconds since 1970 UTC, to determine if 'date' is so far away from current time that a format with the day in it is necessary
    
    Returns:
    
    7 character String of APRS representation of timestamp
  - looksLikeLongFormatLatitude
```
protected static boolean looksLikeLongFormatLatitude(byte[] body,
                                                     int pos,
                                                     int len)
```
    Test the byte array to see if it looks like it contains a APRS text-format (long) position indicator.
    
    Parameters:
    
    body - byte array containing the APRS message
    
    pos - index into the byte array where lat/lon values are supposed to start
    
    len - remaining length of valid message bytes in the array
    
    Returns:
    
    boolean true if a long-format text lat/lon appears to be in the buffer
  - extractComment
```
protected void extractComment(byte[] body,
                              int offset)
```
    Extract the remaining text in the byte buffer as the free-text comment of this message.
    
    Parameters:
    
    body - byte array containing the APRS message
    
    offset - index into the byte array where the free-text comment begins
  - extractComment
```
protected void extractComment(byte[] body,
                              int startPos,
                              int endPos)
```
    Extract the remaining text in the byte buffer as the free-text comment of this message.
    
    Parameters:
    
    body - byte array containing the APRS message
    
    startPos - index into the byte array where the free-text comment begins
    
    endPos - index into the byte array after the free-text comment ends
  - 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, and the override may concatenate the results of the superclass's paramString) method with additional text of its own. This default implementation returns the free-text comment of this APRS message.
    
    Overrides:
    
    paramString in class AX25Message
    
    Returns:
    
    String describing the contents of this message
    
    See Also:
    
    toString(), getComment()
  - formatBody
```
public static java.lang.String formatBody(byte[] body,
                                          int offset)
```
    Convert a byte array into a UTF_8 printable string.
    
    Parameters:
    
    body - byte array
    
    offset - start index into the array
    
    Returns:
    
    String decoded from the trailing part of the byte array
  - getSymbolCode
```
public final char getSymbolCode()
```
    Get the APRS symbol code for this Message.
    
    Returns:
    
    char of the symbol code, or '\0' if this Message does not include a symbol
  - getSymTableId
```
public final char getSymTableId()
```
    Get the APRS symbol table ID or overlay character for this Message.
    
    Returns:
    
    char of the symbol table ID or overlay, or '\0' if this Message does not include a symbol
  - setSymbolCode
```
public void setSymbolCode(char symbolCode)
```
    Set the APRS symbol code for this Message. Generally only meaningful for SendableMessages.
    
    Parameters:
    
    symbolCode - char of the symbol code, or '\0' if this Message should not include a symbol
  - setSymTableId
```
public void setSymTableId(char symTableId)
```
    Set the APRS symbol table ID or overlay character for this Message.
    
    Parameters:
    
    symTableId - char of the symbol table ID or overlay, or '\0' if this Message should not include a symbol
  - decodeWeatherParams
```
protected int decodeWeatherParams(byte[] body,
                                  int offset)
```
    Extract APRS-standard weather information from a message body.
    
    Parameters:
    
    body - byte array of message body
    
    offset - starting position for parsing weather data
    
    Returns:
    
    end position in message body after weather data
  - decodeHurricaneParams
```
protected int decodeHurricaneParams(byte[] body,
                                    int offset)
```
    Extract APRS-standard hurricane/tropical storm information from a message body.
    
    Parameters:
    
    body - byte array of message body
    
    offset - starting position for parsing weather data
    
    Returns:
    
    end position in message body after weather data
  - decodeWeatherParams
```
protected int decodeWeatherParams(java.lang.String body,
                                  int offset)
```
    Extract APRS-standard weather information from a message body.
    
    Parameters:
    
    body - String of message body
    
    offset - starting position for parsing weather data
    
    Returns:
    
    end position in message body after weather data
  - hasWeather
```
public boolean hasWeather()
```
    Report if this Message contains weather information.
    
    Specified by:
    
    hasWeather in class AX25Message
    
    Returns:
    
    boolean true if weather information in this Message
  - getPrecedence
```
public AX25Message.Precedence getPrecedence()
```
    Report the traffic-handling precedence for this message instance. Expected to be overridden by subclasses that have precedence fields.
    
    Overrides:
    
    getPrecedence in class AX25Message
    
    Returns:
    
    Precedence level for this AX25Message
  - getExtensionString
```
public java.lang.String getExtensionString()
```
    Build a formatted string of the weather data known to this message,
    
    Returns:
    
    String in weather comment format
  - getComment
```
public java.lang.String getComment()
```
    Get the free-text comment of this message,
    
    Specified by:
    
    getComment in interface CommentedMessage
    
    Returns:
    
    free-text comment String
  - setComment
```
public void setComment(java.lang.String comment)
```
    Set the free-text comment for this Message. Note this is only meaningful for SendableMessages.
    
    Specified by:
    
    setComment in interface CommentedMessage
    
    Parameters:
    
    comment - String free-text comment to associate with this Message
  - isSymbolInferred
```
public boolean isSymbolInferred()
```
    Report whether the non-null APRS symbol reported by this message is explicit or inferred from destination or source callsign. Intended to be overridden by message types which can infer a symbol but can't explicitly specify the symbol.
    
    Returns:
    
    boolean true if symbol is inferred
  - inferSymbol
```
protected void inferSymbol(AX25Callsign src,
                           AX25Callsign dst)
```
    Decode a symbol from the destination AX25Callsign (handling the case of old hardware and/or software whose limited message set does not include messages with symbol codes in the message body). This handles the GPSxyz, GPSCnn, GPSEnn, SPCxyz, and SYMxyz tocalls, per chapter 20 of the APRS Protocol Reference, V1.0.1.
    
    Parameters:
    
    src - source AX25Callsign to parse (assuming this Message was not relayed through a third-party network), or null to not use source SSID as final fallback
    
    dst - destination AX25Callsign to parse (assuming this Message was not relayed through a third-party network)
  - extractSymbol
```
public static java.lang.String extractSymbol(java.lang.String dest)
```
    Decode a symbol from the destination tocall (handling the case of old hardware and/or software whose limited message set does not include messages with symbol codes in the message body). This handles the GPSxyz, GPSCnn, GPSEnn, SPCxyz, and SYMxyz tocalls, per chapter 20 of the APRS Protocol Reference, V1.0.1.
    
    Parameters:
    
    dest - destination String to parse
    
    Returns:
    
    APRS symbol table and code for the specified destination, or null if not determinable
  - dup
```
public AX25Message dup()
```
    Creates and returns a deep copy of this Message.
    
    Overrides:
    
    dup in class AX25Message
    
    Returns:
    
    a clone of this instance.
    
    See Also:
    
    Cloneable
  - 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.
    
    Overrides:
    
    getProtocols in class AX25Message
    
    Returns:
    
    array of supported ProtocolFamily enums
  - isAppendCR
```
public static boolean isAppendCR()
```
    Indicate whether trailing CR should be appended to generated APRS packets.
    
    Returns:
    
    boolean true if CR control character should be appended, false if not
  - setAppendCR
```
public static void setAppendCR(boolean appendCR)
```
    Specify whether trailing CR should be appended to generated APRS packets.
    
    Parameters:
    
    appendCR - boolean true if CR control character should be appended, false if not

Class Message

Nested Class Summary

Nested classes/interfaces inherited from class org.ka2ddo.ax25.AX25Message

Field Summary

Fields inherited from class org.ka2ddo.ax25.AX25Message

Constructor Summary

Method Summary

Methods inherited from class org.ka2ddo.ax25.AX25Message

Methods inherited from class java.lang.Object

Field Detail

S_PERMANENT

S_PERMANENT_UC

APRS_AND_OPENTRAC_AND_RAW

appendCR

symTableId

symbolCode

comment

msgType

APRS_AND_RAW

Constructor Detail

Message

Message

Method Detail

bodyEquals

compareTo

toString

getMsgType

decodeTimestamp

decodeDatestamp

encodeTimestamp

looksLikeLongFormatLatitude

extractComment

extractComment

paramString

formatBody

getSymbolCode

getSymTableId

setSymbolCode

setSymTableId

decodeWeatherParams

decodeHurricaneParams

decodeWeatherParams

hasWeather

getPrecedence

getExtensionString

getComment

setComment

isSymbolInferred

inferSymbol

extractSymbol

dup

getProtocols

isAppendCR

setAppendCR