SK.gnome.dwarf.main
Class Command

java.lang.Object
  SK.gnome.dwarf.GenericService
      SK.gnome.dwarf.thread.ThreadService
          SK.gnome.dwarf.main.Command

All Implemented Interfaces:

java.lang.Runnable, Service

Direct Known Subclasses:

AuthCmd, CSCmd, DebugCmd, DumpCmd, ExecCmd, HelpCmd, LSCmd, NSLookupCmd, ParamCmd, PasswdCmd, PolicyCmd, PropertiesCmd, ReportCmd, RestartCmd, ShutdownCmd, ThreadsCmd, TraceCmd

public abstract class Command

extends ThreadService

Defines abstract console command.

Command services may be added (plugged-in) to any Server implementation. The Console service then makes them accessible to the end-user through one of the input channels (e.g. an interactive command prompt, a remote network connection, etc.), or they can be executed directly by an other service.

The abstract getDescription() and execute(Subject, Service, String[], Writer) methods must be implemented by the subclasses.

The printHelp(PrintWriter) method may be overriden to provide a detailed instructions on the command usage.

Field Summary

Fields inherited from class SK.gnome.dwarf.thread.ThreadService

daemon, thread

Fields inherited from class SK.gnome.dwarf.GenericService

initParameters, parent

Fields inherited from interface SK.gnome.dwarf.Service

INITIALIZED, LOG_DEBUG, LOG_ERROR, LOG_FATAL, LOG_INFO, LOG_TRACE, LOG_WARN, LOG_XFER, SHUTDOWN, STARTED, STOPPED

Constructor Summary

Command(java.lang.String name)
Creates a new Command.

Method Summary

protected abstract void	execute(javax.security.auth.Subject subject, Service service, java.lang.String[] args, java.io.Writer out) Executes the command.
abstract java.lang.String	getDescription() Returns the command description.
void	printHelp(java.io.PrintWriter out) Prints the command help.

Methods inherited from class SK.gnome.dwarf.thread.ThreadService

enableThread, finish, loop, run, setDaemon, shutdown, start, stop

Methods inherited from class SK.gnome.dwarf.GenericService

getAuthenticator, getAuthFacility, getFullName, getInitParameter, getInitParameterNames, getLogFacility, getLogger, getName, getParameters, getPrincipal, getShutdownTimeout, getState, init, log, log, login, logout, setAuthFacility, setInitParameters, setLogFacility, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Command

public Command(java.lang.String name)

Creates a new Command.

The name of the command is typically a name by which the command will be invoked.

Method Detail

getDescription

public abstract java.lang.String getDescription()

Returns the command description.

It should return a short one-line command description.

Returns:

the command description

printHelp

public void printHelp(java.io.PrintWriter out)

Prints the command help.

By default it prints the string returned from the getDescription() method. It may be overriden to provide more detailed help on the command usage.

Parameters:

out - the output Writer

execute

protected abstract void execute(javax.security.auth.Subject subject,
                                Service service,
                                java.lang.String[] args,
                                java.io.Writer out)
                         throws CommandException

Executes the command.

Executes the command action. This method is called by the console's Console.execute(Subject, String, Writer) method. The service parameter contains a reference to the current working service of the subject executing the command. Command arguments are passed in via the string array args and the command output is redirected to the out stream. The command should throw a CommandException in the case of an error.

Parameters:

subject - the subject executing the command

service - the current working service

args - the command arguments

out - the output stream

Throws:

CommandException - if the command fails for any reason