Package jmri.jmrix

Class NetMessage

java.lang.Object
jmri.jmrix.NetMessage
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
Mx1Message
public abstract class NetMessage extends Object implements Serializable
Represents a single general command or response.

Content is represented with ints to avoid the problems with sign-extension that bytes have, and because a Java char is actually a variable number of bytes in Unicode.

Both a set of indexed contents, an opcode, and a length field are available. Different implementations will map the opcode and length into the contents in different ways. They may not appear at all...

See Also:

  • Constructor Details

    • NetMessage

      public NetMessage(int len)
      Create a new object, representing a specific-length message.
      Parameters:
      len - Total bytes in message, including opcode and error-detection byte.

  • Method Details

    • setOpCode

      public void setOpCode(int i)

    • getOpCode

      public int getOpCode()

    • getOpCodeHex

      public String getOpCodeHex()
      Get a String representation of the op code in hex.
      Returns:
      string of Opcode, 0x format.

    • getNumDataElements

      public int getNumDataElements()
      Get length, including op code and error-detection byte
      Returns:
      total number of data elements.

    • getElement

      public int getElement(int n)

    • setElement

      public void setElement(int n, int v)

    • toString

      public String toString()
      Get a String representation of the entire message in hex. This is not intended to be human-readable!
      Overrides:
      toString in class Object

    • checkParity

      public abstract boolean checkParity()
      check whether the message has a valid parity
      Returns:
      true if parity valid, else false.

    • setParity

      public abstract void setParity()
      Set parity to be correct for this implementation. Note that parity is really a stand-in for whatever error checking, etc needs to be done

    • lowByte

      protected static int lowByte(int val)

    • highByte

      protected static int highByte(int val)