Refresh page (browser button) leads to save item to database again

Question

Situation:

• imagine one form for adding items to the database
• user correctly fill the form and using Save button (h:commandButton) save the item into the DTB
• lifecycle of saved object is finished and form is cleared
• after that, user (don't ask me why:-)) press the refresh button of the browser
• and result is => there are two almost the same items in the DTB (different just in create time)

How can I prevent that behaviour?

Answer 1

Two ways:

1. Use ajax to execute the action (this doesn't generate browser history).

   <h:commandButton ...>
       <f:ajax execute="@form" render="@form" />
   </h:commandButton>
   

2. Send a redirect after post (known as POST-Redirect-GET pattern).

   public String save() {
       // ...
       return "sameview?faces-redirect=true";
   }