[FIXED] Servlet controller - Redirect with parameters

Issue

I'm using Spring MVC web app: Servlet + JSP + Hibernate. This is a part from my CustomerController.java

@RequestMapping(value="/CustomerList", method = RequestMethod.GET)
public ModelAndView customerList() {
    ModelAndView model = new ModelAndView();
    model.setViewName("Customer.List"); // for Tiles View
    model.addObject("listCustomer", DAO_Customer.getListCustomer());
    return model;
}

@RequestMapping(value="/Customer/{id}/Delete", method = RequestMethod.GET)
public String deleteCustomer(@PathVariable("id") int id, Model model) {
    boolean isSuccess = DAO_Customer.deleteCustomer(id);
    if (!isSuccess) {
        model.addAttribute("error", "Failed");
    }
    model.addAttribute("success", "Successed");

    return "redirect:/CustomerList";
}

and here is the code in CustomerList.jsp file to display:

...
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<c:if test="${not empty error}">
    <p>${error}</p>
</c:if>
<c:if test="${not empty success}">
    <p>${success}</p>
</c:if>
...

I want to redirect to /CustomerList and include parameters error + success.
The problem is, when I run, it return /CustomerList?success=Successed and nothing show up expect the default customer list

I search a lot but really don't know how to do what I want. Thanks everyone for read and help.

Solution

You can try with RedirectAttributes#addAttribute.

@RequestMapping(value="/Customer/{id}/Delete", method = RequestMethod.GET)
public String deleteCustomer(@PathVariable("id") int id, RedirectAttributes redirectAttributes) {
  boolean isSuccess = DAO_Customer.deleteCustomer(id);
  if (!isSuccess) {
    redirectAttributes.addAttribute("error", "Failed");
  } else{ //also required
    redirectAttributes.addAttribute("success", "Successed");
  }
  return "redirect:/CustomerList";
}

In this case, the url will turn into /CustomerList?success=Successed if successful.

And you can access param value with EL as follows:

${param.success} or ${param.error}

---

Also you can use RedirectAttributes#addFlashAttribute.

redirectAttributes.addFlashAttribute("success", "Successed");

Then you can access directly as ${success} or ${error}.

Answered By - Gurkan Yesilyurt