When handling POST requests, these steps should be done in the handler method:
Consume POST data
Update application state (for example update external database, send data to external service, ...)
Send a 302 "moved temporarily" response and redirect to the page the request came from so that a page reload won't change the application state again. See Section 4.3.6.5, “Handling redirects”
If needed, status information can be transferred from the handler to the following (redirected) request using flash attributes, see Section 4.3.6.5.3, “Preserving attributes in a redirect”
 |  |  |
 |