henplus.commands
Class SystemInfoCommand

java.lang.Object
  extended by henplus.AbstractCommand
      extended by henplus.commands.SystemInfoCommand
All Implemented Interfaces:
Command

public final class SystemInfoCommand
extends AbstractCommand

Prints out some system information.
Created on: Mar 23, 2004


Field Summary
 
Fields inherited from interface henplus.Command
EXEC_FAILED, SUCCESS, SYNTAX_ERROR
 
Constructor Summary
SystemInfoCommand()
           
 
Method Summary
 int execute(SQLSession session, String command, String parameters)
          execute the command given.
 String[] getCommandList()
          returns the prefices of all command-strings this command can handle.
 String getLongDescription(String cmd)
          returns a longer string describing this action.
 String getShortDescription()
          return a short string describing the purpose of the commands handled by this Command-implementation.
 String getSynopsis(String cmd)
          retuns a synopsis-string.
 boolean participateInCommandCompletion()
          returns 'false', if the commands supported by this Commands should not be part of the toplevel command completion.
 boolean requiresValidSession(String cmd)
          returns true, if this command requires a valid SQLSession, i.e.
 
Methods inherited from class henplus.AbstractCommand
argumentCount, complete, getOption, getOptions, handleCommandline, isComplete, registerOptions, setOptions, shutdown
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SystemInfoCommand

public SystemInfoCommand()
Method Detail

getCommandList

public String[] getCommandList()
Description copied from interface: Command
returns the prefices of all command-strings this command can handle. The special prefix is the empty string that matches anything that is not handled by all other commands. It is used in the SQLCommand.


participateInCommandCompletion

public boolean participateInCommandCompletion()
Description copied from interface: Command
returns 'false', if the commands supported by this Commands should not be part of the toplevel command completion. So if the user presses TAB on an empty string to get the full list of possible commands, this command should not show up. In HenPlus, this returns 'false' for the SQL-commands ('select', 'update', 'drop' ..), since this would clobber the toplevel list of available commands. If unsure, return 'true'.

Specified by:
participateInCommandCompletion in interface Command
Overrides:
participateInCommandCompletion in class AbstractCommand

execute

public int execute(SQLSession session,
                   String command,
                   String parameters)
Description copied from interface: Command
execute the command given. The command is given completely without the final delimiter (which would be newline or semicolon). Before this method is called, the CommandDispatcher checks with the Command.isComplete(String) method, if this command is complete.

Parameters:
session - the SQLsession this command is executed from.
command - the command as string.
parameters - the rest parameters following the command.
Returns:
one of SUCCESS, SYNTAX_ERROR, EXEC_FAILED to indicate the exit status of this command. On SYNTAX_ERROR, the CommandDispatcher displays a synopsis if available.

requiresValidSession

public boolean requiresValidSession(String cmd)
Description copied from interface: Command
returns true, if this command requires a valid SQLSession, i.e. if the Command.execute(SQLSession,String,String) method makes use of the session (e.g. to get some Database connection) or not. Return 'true' if unsure (you should be sure..). This is to thwart attempts to execute a command without session.

Specified by:
requiresValidSession in interface Command
Overrides:
requiresValidSession in class AbstractCommand
Parameters:
cmd - the subcommand this is requested for; one of the commands returned by Command.getCommandList().

getShortDescription

public String getShortDescription()
Description copied from interface: Command
return a short string describing the purpose of the commands handled by this Command-implementation. This is the string listed in the bare 'help' overview (like 'describe a database object') Should contain no newline, no leading spaces.

Specified by:
getShortDescription in interface Command
Overrides:
getShortDescription in class AbstractCommand

getSynopsis

public String getSynopsis(String cmd)
Description copied from interface: Command
retuns a synopsis-string. The synopsis string returned should follow the following conventions:

Should contain no newline, no leading spaces. This synopsis is printed in the detailed help of a command or if the execute()-method returned a SYNTAX_ERROR.

Specified by:
getSynopsis in interface Command
Overrides:
getSynopsis in class AbstractCommand
Parameters:
cmd - the command the synopsis is for. This is one of the possible commands returned by Command.getCommandList().

getLongDescription

public String getLongDescription(String cmd)
Description copied from interface: Command
returns a longer string describing this action. This should return a String describing details of the given command. This String should start with a TAB-character in each new line (the first line is a new line). The last line should not end with newline.

Specified by:
getLongDescription in interface Command
Overrides:
getLongDescription in class AbstractCommand
Parameters:
cmd - The command the long description is asked for. This is one of the possible commands returned by Command.getCommandList().


? 1997..2006 Henner Zeller