de.frame4j.security

Interface Permit.Operable

Enclosing class:

Permit

public static interface Permit.Operable

Controllable (remotely) function unit.

Objects of classes implementing this interface accept operator's orders in the form of a character sequence: no more, but not less. Examples are: "stop fuel pump", "ventilate boiler" or just "ventilate", "stop", "start", "halt" or things like e.g.
"makeNewUser muppi Kermit Frosch customerRole".

These orders or commands to the implementing object in question have either to be executed or rejected. In either case the returned answer must be a clearly stated human readable (!) text, preferably with some common parsable first words (reject, error, success, Fehler, ausgeführt) understood in the applications domain.


Copyright 2004 Albrecht Weinert

Version:

see enclosing class

Author:

Albrecht Weinert

Method Summary

Modifier and Type	Method and Description
String	clientOrder(String command) Command or order by a client.

Method Detail

clientOrder

String clientOrder(String command)
            throws IllegalArgumentException

Command or order by a client.

This method will be called if a (may be remote) client has an order to this (the implementing class's) object out of a set of orders agreed upon. The parameter command is or starts (white space separated) with such an order that may be followed by any command parameters in a form also agreed upon. Usual is the command shell syntax of white space separated parameters, having to be enclosed in quotation marks if itself containing white spaces (like foolish directory or file names).

The String returned by this method is a clearly stated human readable (!) text describing and acknowledging the successful execution of the order.
In the case of rejection or failure this text shall start with one (parsable) keyword from a small set agreed upon, that will never be used in fist place in case of success. A good set is: rejected, error, failure, (impossible).

The last case (impossible) cause of not implemented command or syntactically incorrect parameters shall (better) be signalled by an IllegalArgumentException with a distinct (human) readable message.

Hint: This method may be used to implement or support JMX controlling and observing.

Parameters:

command - the order; not to be null or empty

Returns:

positive or negative acknowledgement

Throws:

IllegalArgumentException - if the given command is not implemented or the command is syntactically not acceptable