Issue
I'm new in Spring, and I'm trying to better undestand the MVC framework. Considering the following jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Hello World!</title>
</head>
<body>
Welcome <%=request.getAttribute("username")%>
</body>
</html>
I see that, in a @Controller class:
@GetMapping("/EntryPoint1")
public String helloView1(Model model) {
model.addAttribute("username", "pippo");
return "HelloWorld";
}
it uses as username value the one inserted in model.
However, if I declare both the Model model parameter and I return a ModelAndView object, that is:
@GetMapping("/EntryPoint2")
public ModelAndView helloView2(Model model) {
model.addAttribute("username", "pluto");
ModelAndView mav = new ModelAndView("HelloWorld");
mav.addObject("username", "paperino");
return mav;
}
I obtain that the value used by the view is the one contained in mav ignoring the value in model. Is there an explanation for this (for example, any kind of precedence between the objects considered by the view)?
Solution
see, here in model.addAttribute("username", "pluto"); and in mav.addObject("username", "paperino"); username is same so priorities goes to ModelAndView, However u change the name then u can render them both and access.
Answered By - manish
