Avoid Spring MVC form resubmission when refreshing the page - spring

Question

I am using spring MVC to save the data into database. Problem is it's resubmitting the JSP page when I am refreshing the page.
Below is my code snippet
<c:url var="addNumbers" value="/addNumbers" ></c:url>
<form:form action="${addNumbers}" commandName="AddNumber" id="form1">
</<form:form>
#RequestMapping(value = "/addNumbers", method = RequestMethod.POST)
public String addCategory(#ModelAttribute("addnum") AddNumber num){
this.numSrevice.AddNumbers(num);
return "number";
}

Answer 1

You have to implement Post/Redirect/Get.
Once the POST method is completed instead of returning a view name send a redirect request using "redirect:<pageurl>".
#RequestMapping(value = "/addNumbers", method = RequestMethod.POST)
public String addCategory(#ModelAttribute("addnum") AddNumber num){
this.numSrevice.AddNumbers(num);
return "redirect:/number";
}
And and have a method with method = RequestMethod.GET there return the view name.
#RequestMapping(value = "/number", method = RequestMethod.GET)
public String category(){
return "number";
}
So the post method will give a redirect response to the browser then the browser will fetch the redirect url using get method since resubmission is avoided
Note: I'm assuming that you don't have any #RequestMapping at controller level. If so append that mapping before /numbers in redirect:/numbers

Answer 2

You can return a RedirectView from the handler method, initialized with the URL:
#RequestMapping(value = "/addNumbers", method = RequestMethod.POST)
public View addCategory(#ModelAttribute("addnum") AddNumber num,
HttpServletRequest request){
this.numSrevice.AddNumbers(num);
String contextPath = request.getContextPath();
return new RedirectView(contextPath + "/number");
}

Answer 3

My answer shows how to do this, including validation error messages.
Another option is to use Spring Web Flow, which can do this automatically for you.