uk.org.ogsadai.client.databrowser.commands
Class Command

java.lang.Object
  |
  +--java.util.Observable
        |
        +--uk.org.ogsadai.client.databrowser.commands.Command

All Implemented Interfaces:

java.awt.event.ActionListener, java.util.EventListener

Direct Known Subclasses:

SQLBagCommand, SQLQueryCommand, SQLResilientCommand, SQLUpdateCommand, XPathQueryCommand, XQueryCommand

public abstract class Command

extends java.util.Observable

implements java.awt.event.ActionListener

Encapulates commands to be sent to the database. Commands are essentially queries or updates.

Author:

OGSA-DAI team

mController

protected DBQueryController mController

Controller to use when executing the command.

Command

public Command(DBQueryController?controller)

Constructor

Parameters:

controller -

executeRequest

public abstract java.lang.Object executeRequest(DBDataResource?resource,
                                                java.lang.String?expression)
                                         throws java.lang.Exception

Executes a request to a data resource.

Parameters:

resource - The data resource to which to send the request.

expression - The query expression to send.

Returns:

A object whose actual type is dependent on the type of command.

Throws:

java.lang.Exception - If a problem is encountered when executing the request.

getResultView

public abstract ResultView getResultView(javax.swing.JFrame?parent)

Gets the view which will display the results of this command.

Parameters:

parent - The parent frame.

Returns:

The view which will display the command's results.

actionPerformed

public void actionPerformed(java.awt.event.ActionEvent?event)

Specified by:

actionPerformed in interface java.awt.event.ActionListener

updateObservers

public void updateObservers(java.lang.Object?obj)

Notifies observers.

Parameters:

obj -