to.etc.telnet

Interface ITelnetCommandHandler

public interface ITelnetCommandHandler

This interface allows easy extension of the available telnet commands by allowing a user to add commands to the set. This is typically done by creating a class inplementing this interface, and then registering the class by calling LogMaster.registerTelnetCommand. Usually an anonymous class is used for this, because the actual command handler is usually a static member of a given class. A typical registration for such a static thing could be:

  //-- Add the logmaster command handler.
  iTelnetCommandHandler lh = new iTelnetCommandHandler()
  {
     public boolean executeTelnetCommand(TelnetPrintWriter tpw, CmdStringDecoder commandline) throws Exception
     {
        return MyClass.executeTelnetCommand(tpw, commandline);
     }
  };
  LogMaster.registerTelnetCommand(lh);
  

The telnet command handler returns TRUE if it has executed the command and false if not. For all entered commands ALL handlers are ALWAYS called, so you must take care NOT to report an error if you do not recognise a command. If a command is NOT recognised by any registered handler an error message is output to the issuing session. A typical implementation of a command handler would be:

  static protected boolean executeTelnetCommand(TelnetPrintWriter ts, CmdStringDecoder cmd) throws Exception
  {
                if(cmd.currIs("?"))  // Help command (global)?
                {
                        ts.println(USAGE);
                        return true;
                }
                if(! cmd.currIs("myclass")) return false;       // all my commands start with myclass

                if(! cmd.hasMore() || cmd.currIs("?"))          // myclass ? is my usage exclusively.
                {
                        ts.println(USAGE);
                        return true;
                }
                else if(cmd.currIs("fil*"))                                     // myclass file?
                {
                        .... handle this command....
      }
      return false; // Unrecognised!
  }
  

Author:

Frits Jalvingh

Method Summary

Modifier and Type	Method and Description
boolean	executeTelnetCommand(TelnetPrintWriter tpw, CmdStringDecoder commandline)

Method Detail

executeTelnetCommand

boolean executeTelnetCommand(TelnetPrintWriter tpw,
                             CmdStringDecoder commandline)
                      throws Exception

Throws:

Exception