Spring MVC doesn't display data in view

Question

Possible Duplicate:
JSP: EL expression is not evaluated

I have the following code in my controller.

@RequestMapping(value = "/sum", method = RequestMethod.GET)
public String sum(@RequestParam("input1") String value1,
        @RequestParam("input2") String value2, ModelMap model) {
    model.addAttribute(
            "msg",
            Integer.toString(Integer.parseInt(value1)
                    + Integer.parseInt(value2)));
    return "index";
}

Following is my view:

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<html>
<body>
<h2>Hello World!</h2>
<h2>Movie Name : <c:out value="${msg}"></c:out></h2>    
</body>
</html>

But my output is

Hello World!
Movie Name : ${msg}

Where am i wrong?

I've seen several questions like this before, you might search those out. [Here is one](http://stackoverflow.com/questions/793983/jsp-el-expression-is-not-evaluated), [here is another](http://stackoverflow.com/questions/2168832/expression-language-in-jsp-not-working), and [here is another](http://stackoverflow.com/questions/1721518/el-expressions-wont-executed-in-tomcat-5-5-but-working-in-tomcat-6-0-20/1721665). — Beau Grantham, Dec 22 '11 at 21:05
Are you aware that Spring can do type conversion for you and that you can make the method parameters `Integer`, avoiding the manual type conversion? — Dave Newton, Dec 22 '11 at 21:30
This answer: http://stackoverflow.com/questions/1529184/jsps-not-displaying-objects-from-model-in-spring may be helpful. — Bill, Dec 22 '11 at 21:55

score 2 · Accepted Answer · answered Dec 23 '11 at 07:46

2

This is because jstl library is not available. Either copy it to WEB-INF/lib or copy that directly to Tomcat/lib directory and restart Tomcat.

answered Dec 23 '11 at 07:46

Mobiz Tech Team

182
3
12

score 0 · Answer 2 · answered Dec 22 '11 at 21:39

0

You're returning a View String "index" but your model is not being sended/attached to the response view, so $msg is not found/bound in your JSP

Try this

 @RequestMapping(value = "/sum", method = RequestMethod.GET)
 public ModelAndView sum(@RequestParam("input1") String value1, @RequestParam("input2") String value2, ModelMap model) {
        model.addAttribute( "msg", Integer.toString(Integer.parseInt(value1) + Integer.parseInt(value2)));
        return new ModelAndView("index", model);
 }

answered Dec 22 '11 at 21:39

Carlos Quijano

1,566
15
23

I don't believe this is correct--you can return a string to indicate the view to be rendered, objects in the model are still exposed. – Dave Newton Dec 22 '11 at 21:45
The view would simply not print anything if this were the case. Spring carries `model` forward when returning a `String`, so changing the method to return a `ModelAndView` is not necessary in this case. – Beau Grantham Dec 22 '11 at 21:47

Spring MVC doesn't display data in view

2 Answers2