How do you prevent a user from posting data multiple times on a website

Question

I am working on a web application (J2EE) and I would like to know the options that are available for handling a double post from the browser.

The solutions that I ha

Answer 1

Two server-side solutions come to mind:

1. Create one-time use "tokens" in a hidden form field. Once a token is used, it is deleted from whatever database or session context object you're storing it in. The second time, it's not accepted.
2. Cache information received, and if an identical form is received within a certain time period (10 minutes? an hour? You decide!) it is ignored.