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

Field Summary

protected DBQueryController

mController Controller to use when executing the command.

Fields inherited from class java.util.Observable

Constructor Summary

Command(DBQueryController controller)
Constructor

Method Summary

void	actionPerformed(java.awt.event.ActionEvent event)
abstract java.lang.Object	executeRequest(DBDataResource resource, java.lang.String expression) Executes a request to a data resource.
abstract ResultView	getResultView(javax.swing.JFrame parent) Gets the view which will display the results of this command.
void	updateObservers(java.lang.Object obj) Notifies observers.

Methods inherited from class java.util.Observable

addObserver, clearChanged, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers, setChanged

Methods inherited from class java.lang.Object

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

Field Detail

mController

protected DBQueryController mController

Controller to use when executing the command.

Constructor Detail

Command

public Command(DBQueryController controller)

Constructor

Parameters:

controller -

Method Detail

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 -