Double submit problem

[amitev]

Hi all! I have the following situation:

Page for updating information (adding new associations to a list) and update button the action method is

 @In @Out
 private Project project;

 public void updateProject() {
 project = em.merge(project);
 }

The problem is that if the user submits the form more than once before the new page is displayed, the state of the entity is propagated to the db more than one time. Is there a way to solve this?

[amitev]

Ideas?

[michael.yuan]

Use the Redirect-After-Post pattern:

http://www.theserverside.com/tt/articles/article.tss?l=RedirectAfterPost

This is easy in JSF -- just add tag to your page navigation rule.

[michael.yuan]

I mean, add the

<redirect/>

tag

[amitev]

Thank you for the answer. In my page.xml i already have:

<navigation from-action="#{projectAction.updateProject}">
 <redirect view-id="/pages/project/details.xhtml" />
</navigation>

But this does not solve the problem. The problem comes from em.merge() method. Each time it is invoked it saves the changes (don't know why because it performs a select query and should save the changes only once).