Synchronization Token

[Hideki Mae]

To all:
Can anybody tell me how to use synchronization token? I have the following on an Action and it will always return false.
boolean valid = isTokenValid(httpServletRequest);
if(valid){
resetToken(httpServletRequest);
System.out.println("The token is valid");
}else{
System.out.println("The token is invalid");
}
This is to prevent resubmission of the page.
I thought you simply check if the token is valid. If it is, you would reset the token. If not, than you would handle the error.
Do I need to add anything to my web page?
Is there a specific link that explains synchronization token? The places I came across were bits and pieces of information and not too specific.

Thank you in advance.

[Lucian Ochian]

Take a look here: http://www.coderanch.com/t/51602/Struts/Duplicate-form-submission-Synchronizer-Token

It works like a dream, thanks to Ravindra Janapareddy that explained this pattern very well and simple.

So you only thing that have to add is to save the token in the loading Action.

Lucian

[Hideki Mae]

Thank you for replying. I tried it on one of my web pages. It seems to alternate between valid and invalid when I execute the action. What I have are two actions. The first action is for the initial load of the page (similar to DisplayAction in the example). The 2nd Action executes a query on the database and sets up the data to be displayed (similar to SubmitAction). The web page has one button which will execute the 2nd Action each time I press a button. When I press it the first time the data gets loaded and isTokenValid() will return true. If I press the button again, (basically I am executing another query) it will become invalid. And the validation alternates each time I execute the 2nd action (press the button). Am I doing something wrong?
Thanks for any information you can give me.

[Hideki Mae]

I figured out that all I needed to do was add saveToken() after the resetToken() statement. It is working now.
Thank you for all your help.

[Lucian Ochian]

Be careful!
Take a look again to the link that I gave you because I added a post reply there!

Regards,
Lucian

[Hideki Mae]

Thank you. It helped alot.