jmri.jmrix.can.CanMessage

All Implemented Interfaces:: CanFrame, CanMutableFrame, Message

public class CanMessage extends AbstractMRMessage implements CanMutableFrame

Base class for messages in a CANbus based message/reply protocol.

It is expected that any CAN based system will be based upon basic CANbus concepts such as ID (standard or extended), Normal and RTR frames and a data field.

The _dataChars[] and _nDataChars members refer to the data field, not the entire message.

"header" refers to the full 11 or 29 bit header; which mode is separately set via the "extended" parameter

CBUS uses a 2-bit "Pri" field and 7-bit "ID" ("CAN ID") field, with separate accessors. CBUS ID is set as a layout connection preference and registered by the traffic controller.

Field Summary

Fields

Modifier and Type

Field

Description

(package private) int

_header

(package private) boolean

_isExtended

(package private) boolean

_isRtr

Fields inherited from class jmri.jmrix.AbstractMRMessage
LONG_TIMEOUT, SHORT_TIMEOUT, sourceLetter

Fields inherited from class jmri.jmrix.AbstractMessage
_dataChars, _nDataChars
Constructor Summary

Constructors

Constructor

Description

CanMessage(byte[] d, int header)

Create a new CanMessage from a byte array

CanMessage(int header)

Create a new CanMessage with 8 data bytes

CanMessage(int[] d, int header)

Create a new CanMessage from an int array

CanMessage(int numDataBytes, int header)

Create a new CanMessage of given length

CanMessage(CanMessage m)

Create a new CanMessage from an existing CanMessage

CanMessage(CanReply m)

Create a new CanMessage from an existing CanReply
Method Summary

Modifier and Type

Method

Description

boolean

equals(Object a)

Note that a CanMessage and a CanReply can be tested for equality.

int[]

getData()

Get the data bytes in array form.

int

getElement(int n)

Get a particular element in a Message.

int

getHeader()

Get the CAN Frame header.

int

getNumDataElements()

Get the number of data elements in a Message.

int

hashCode()

Hash on the header

boolean

isExtended()

Get if the CAN Frame has an extended header.

boolean

isRtr()

Get if the CAN Frame is an RTR Frame.

boolean

isTranslated()

Check if translation flag has been set.

boolean

replyExpected()

Is a reply expected to this message?

void

setElement(int n, int v)

Set a single Data Element at a particular index.

void

setExtended(boolean b)

Set if the CAN Frame header is extended.

void

setHeader(int h)

Set the CAN Frame header.

final void

setNumDataElements(int n)

Set the number of data elements in the main CAN Frame body.

void

setRtr(boolean b)

Set if the CAN Frame is an RTR Frame.

void

setSourceLetter(String source)

void

setTranslated(boolean translated)

Tag whether translation is needed.

String

toMonitorString()

This format matches CanReply

String

toString()

This format matches CanReply

Methods inherited from class jmri.jmrix.AbstractMRMessage
addIntAsFourHex, addIntAsThree, addIntAsThreeHex, addIntAsTwoHex, getNeededMode, getOpCode, getOpCodeHex, getRetries, getSourceLetter, getTimeout, isBinary, setBinary, setNeededMode, setOpCode, setRetries, setTimeout

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface jmri.jmrix.can.CanFrame
appendHexElements, dataFramesEqual, extendedOrRtr, getToString, isEqual, monString

Methods inherited from interface jmri.jmrix.can.CanMutableFrame
setData, setData

Field Details
- _header
  
  int _header
- _isExtended
  
  boolean _isExtended
- _isRtr
  
  boolean _isRtr
Constructor Details
- CanMessage
  
  public CanMessage(int header)
  
  Create a new CanMessage with 8 data bytes
  
  Parameters:
  
  header - The CAN Frame header value
- CanMessage
  
  public CanMessage(int numDataBytes, int header)
  
  Create a new CanMessage of given length
  
  Parameters:
  
  numDataBytes - number of CAN Frame data bytes, max 8
  
  header - The CAN Frame header value
- CanMessage
  
  public CanMessage(int[] d, int header)
  
  Create a new CanMessage from an int array
  
  Parameters:
  
  d - array of CAN Frame data bytes, max 8
  
  header - The CAN Frame header value
- CanMessage
  
  public CanMessage(byte[] d, int header)
  
  Create a new CanMessage from a byte array
  
  Parameters:
  
  d - array of CAN Frame data bytes, max 8
  
  header - The CAN Frame header value
- CanMessage
  
  public CanMessage(@Nonnull CanMessage m)
  
  Create a new CanMessage from an existing CanMessage
  
  Parameters:
  
  m - The existing CanMessage
- CanMessage
  
  public CanMessage(@Nonnull CanReply m)
  
  Create a new CanMessage from an existing CanReply
  
  Parameters:
  
  m - The existing CanReply
Method Details
- setTranslated
  
  public void setTranslated(boolean translated)
  
  Tag whether translation is needed. a "native" message has been converted already.
  
  Parameters:
  
  translated - true or false to set flag as required
- isTranslated
  
  public boolean isTranslated()
  
  Check if translation flag has been set.
  
  Returns:
  
  false by default
- hashCode
  
  public int hashCode()
  
  Hash on the header
  
  Overrides:
  
  hashCode in class AbstractMessage
  
  Returns:
  
  hashcode from sum of elements.
- equals
  
  public boolean equals(Object a)
  
  Note that a CanMessage and a CanReply can be tested for equality.
  
  Overrides:
  
  equals in class AbstractMessage
  
  Parameters:
  
  a - CanMessage or CanReply to test against
- toString
  
  public String toString()
  
  This format matches CanReply
  
  Specified by:
  
  toString in interface Message
  
  Overrides:
  
  toString in class AbstractMRMessage
- toMonitorString
  
  public String toMonitorString()
  
  This format matches CanReply
  
  Specified by:
  
  toMonitorString in interface Message
  
  Returns:
  
  a human-readable representation of the message.
- replyExpected
  
  public boolean replyExpected()
  
  Is a reply expected to this message?
  By default, a reply is expected to every message; either a reply or a timeout is needed before the next message can be sent.
  If this returns false, the transmit queue will immediately go on to transmit the next message (if any).
  
  Overrides:
  
  replyExpected in class AbstractMRMessage
  
  Returns:
  
  always false
- getNumDataElements
  
  public int getNumDataElements()
  
  Get the number of data elements in a Message.
  
  Specified by:
  
  getNumDataElements in interface CanFrame
  
  Specified by:
  
  getNumDataElements in interface Message
  
  Overrides:
  
  getNumDataElements in class AbstractMessage
  
  Returns:
  
  number elements.
- setNumDataElements
  
  public final void setNumDataElements(int n)
  
  Set the number of data elements in the main CAN Frame body.
  
  Specified by:
  
  setNumDataElements in interface CanMutableFrame
  
  Parameters:
  
  n - true number of data bytes, 0-8
- getElement
  
  public int getElement(int n)
  
  Get a particular element in a Message.
  
  Specified by:
  
  getElement in interface CanFrame
  
  Specified by:
  
  getElement in interface Message
  
  Overrides:
  
  getElement in class AbstractMessage
  
  Parameters:
  
  n - Element Index.
  
  Returns:
  
  single element of message.
- setElement
  
  public void setElement(int n, int v)
  
  Set a single Data Element at a particular index.
  
  Specified by:
  
  setElement in interface CanMutableFrame
  
  Specified by:
  
  setElement in interface Message
  
  Overrides:
  
  setElement in class AbstractMessage
  
  Parameters:
  
  n - index of element.
  
  v - value of element.
- getData
  
  public int[] getData()
  
  Get the data bytes in array form.
  
  Returns:
  
  the actual int array
- getHeader
  
  public int getHeader()
  
  Get the CAN Frame header.
  
  Specified by:
  
  getHeader in interface CanFrame
  
  Returns:
  
  header value
- setHeader
  
  public void setHeader(int h)
  
  Set the CAN Frame header.
  
  Specified by:
  
  setHeader in interface CanMutableFrame
  
  Parameters:
  
  h - new header value
- isExtended
  
  public boolean isExtended()
  
  Get if the CAN Frame has an extended header.
  
  Specified by:
  
  isExtended in interface CanFrame
  
  Returns:
  
  true if extended, else false
- setExtended
  
  public void setExtended(boolean b)
  
  Set if the CAN Frame header is extended.
  
  Specified by:
  
  setExtended in interface CanMutableFrame
  
  Parameters:
  
  b - true if extended, else false
- isRtr
  
  public boolean isRtr()
  
  Get if the CAN Frame is an RTR Frame.
  
  Specified by:
  
  isRtr in interface CanFrame
  
  Returns:
  
  true if RTR, else false
- setRtr
  
  public void setRtr(boolean b)
  
  Set if the CAN Frame is an RTR Frame.
  
  Specified by:
  
  setRtr in interface CanMutableFrame
  
  Parameters:
  
  b - true if RTR, else false
- setSourceLetter
  
  public void setSourceLetter(String source)

Class CanMessage

Field Summary

Fields inherited from class jmri.jmrix.AbstractMRMessage

Fields inherited from class jmri.jmrix.AbstractMessage

Constructor Summary

Method Summary

Methods inherited from class jmri.jmrix.AbstractMRMessage

Methods inherited from class java.lang.Object

Methods inherited from interface jmri.jmrix.can.CanFrame

Methods inherited from interface jmri.jmrix.can.CanMutableFrame

Field Details

_header

_isExtended

_isRtr

Constructor Details

CanMessage

CanMessage

CanMessage

CanMessage

CanMessage

CanMessage

Method Details

setTranslated

isTranslated

hashCode

equals

toString

toMonitorString

replyExpected

getNumDataElements

setNumDataElements

getElement

setElement

getData

getHeader

setHeader

isExtended

setExtended

isRtr

setRtr

setSourceLetter