Can someone pls explain why ResourceBundle throw nullpointerexception

[Canned]

Hi,
I have a newbie question, I hope you don't mind explaining this problem
to me.
I wrote a class that only have 1 method, like this one

------------------------ResourcesManager.java---------------------
package com.dev.test;

import java.util.ResourceBundle;

public class ResourcesManager {
ResourceBundle resourceBundle = ResourceBundle.getBundle("test");

public String stringFetcher(String key) {
System.out.print(key);
return resourceBundle.getString(key);

}

}
---------------------End code----------------------------

and the second class
-------------------Editor.java--------------------------
package com.dev.test;

import java.util.ResourceBundle;

import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class Editor {
Shell shell;
Display display;

ResourcesManager resources;
//ResourceBundle resources2 = ResourceBundle.getBundle("test");

public void run() {
display = new Display();
Editor editor = new Editor();
shell = editor.open(display);

while (!shell.isDisposed()) {
if (!display.readAndDispatch()) display.sleep();
}
display.dispose();

}

private Shell open(Display display) {
createShell(display);
shell.open();
return shell;

}

private void createShell(Display display) {
shell = new Shell(display);
shell.setText(resources.stringFetcher("Title")); // Throws
nullpointerexcepion
//shell.setText(resources2.getString("Title")); // no exceptions
shell.setSize(600, 800);

}

}
----------------------------End code------------------------------

If I call the method ResourcesManager.stringFetcher() from Editor class,
I will only get NullPointerException, but if I call ResourceBundle
directly from Editor class, it just works as expected. Can someone pls
explain this behavior?

[Bent C Dalager]

On 2009-02-25, Canned <us...@domain.invalid> wrote:
>
> public class Editor {
> Shell shell;
> Display display;
>
> ResourcesManager resources;

This is never initialized to anything so is null. This leads to
NullPointerException when you try to call a method on it.

Try to replace the line with
ResourcesManager resources = new ResourcesManager();

Cheers,
Bent D
--
Bent Dalager - b...@pvv.org - http://www.pvv.org/~bcd
powered by emacs

[Canned]

Bent C Dalager schreef:

> On 2009-02-25, Canned <us...@domain.invalid> wrote:
>> public class Editor {
>> Shell shell;
>> Display display;
>>
>> ResourcesManager resources;
>
> This is never initialized to anything so is null. This leads to
> NullPointerException when you try to call a method on it.
>
> Try to replace the line with
> ResourcesManager resources = new ResourcesManager();
>
> Cheers,
> Bent D

Thank you for your fast reply. You're right, I forgot to initialized
'resource' variable. I feel a little stupid now, asking stupid question
like that. :P

[Lew]

Bent got your NPE straightened out. I'm a little puzzled about the 'run()'
method of 'Editor' creating a brand new instance of 'Editor' and operating on
that instead of its own members.

--
Lew

[Canned]

Lew schreef:

Now that you mention it, I rewrite it like this: shell = open();. I
found an examples from internet and trying to write my own based on
that:
http://www.java2s.com/Code/Java/SWT-JFace-Eclipse/SWTTextEditorDemo.htm

[Roedy Green]

On Thu, 26 Feb 2009 00:17:55 +0100, Canned <us...@domain.invalid>
wrote, quoted or indirectly quoted someone who said :

>NullPointerException

Others will give you specific help. Here is what do to in general.

http://mindprod.com/jgloss/runerrormessages.html#NULLPOINTEREXCEPTION
--
Roedy Green Canadian Mind Products
http://mindprod.com

"If everyone lived the way people do in Vancouver,
we would need three more entire planets to support us."
~ Guy Dauncey (born: 1948 age: 61)