Get the URL of the last request from requests

Turn from: http://www.iteye.com/topic/100178

In the HTTP request object, you can take the HTTP header header, one of which is "Referer", through which we can know the URL of the last request, which is quite useful in some situations.
As in a list page, there is usually a delete link that deletes one of the data in the list, and if you want the deletion to succeed and then return to the list page, you can do the following:

String Returl = Request.getheader ("Referer");  
if (Returl!= null) {   
    response.sendredirect (returl);   
}   

It's just so simple, it's OK.
For add and edit operations, you can do the same, just a little workaround, to pass a referer from the previous page.