forEach not reading a List

**Checkerbelt** · Oct 6th, 2006, 04:01 PM

I've got a Map containing a List of Users given to my jsp. I am trying to iterate through them with a <c:forEach>, and it doesn't like it. My User object is a simple JavaBean. I've used <c:out> on the List within the map and I get the data. Why isn't the <c:forEach> working?

SpringappController.handleRequest()

Code:

    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        Map data = new HashMap();

        List users = getUserManager().getUsers();
        data.put("users", users);
        logger.info("Users: " + users);

        return new ModelAndView("hello", "data", data);
    }

jsp

Code:

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

<html>
<body>
<c:forEach items="${data.users}" var="user">
  <c:out value="${user}"/><br/>
</c:forEach><br/>

<c:out value="${data.users}"/><br/>

<c:out value="${data.users[0].username}"/> - <c:out value="${data.users[0].age}"/><br/>
<c:out value="${data.users[1].username}"/> - <c:out value="${data.users[1].age}"/><br/>
<c:out value="${data.users[2].username}"/> - <c:out value="${data.users[2].age}"/><br/>
</body>
</html>

output

HTML Code:

<html>
<body>

  ${data.users}<br/>
<br/>

[business.User@18f1be9, business.User@717d91, business.User@eafb71]<br/>

Matt - 27<br/>
Jonathan - 24<br/>

Zac - 19<br/>
</body>
</html>

**whipshaw** · Oct 6th, 2006, 09:10 PM

I don't really see why it is outputing ${data.users}?

The code looks right to me as long as there is a toString() common override on your User class.

what happens when you do

Code:

<c:forEach items="${data.users}" var="user">
  <c:out value="${user.username}"/><br/>
</c:forEach><br/>

?

**Checkerbelt** · Oct 7th, 2006, 01:38 PM

I get a blank string. And only one at that, when there are three users in the list.

**mascis** · Oct 9th, 2006, 05:18 PM

FYI, I'm seeing the exact same behavior--first foray into Spring. I'm getting it trying to set up the tutorial code (http://www.springframework.org/docs/...-by-step.html). No resolution yet, but I'll let you know if I figure it out...

**whipshaw** · Oct 9th, 2006, 05:25 PM

The best solution: Switch to using FreeMarker

**Checkerbelt** · Oct 10th, 2006, 06:58 PM

My latest experiments

Code:

    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        ModelAndView mav = new ModelAndView("hello");

        mav.addObject("now", new Date().toString());
        mav.addObject("usernames", userManager.getUsernames());

        return mav;
    }

HTML Code:

  <h2>Now</h2>
  <c:out value="${now}"/>

  <h2>Usernames</h2>
  <ul>
  <c:forEach items="${usernames}" var="username">
    <li><c:out value="${username}"/></li>
  </c:forEach>
  </ul>

  <h2>Usernames array</h2>
  <c:out value="${usernames}"/>

  <h2>Numbers</h2>
  <c:forEach var="i" begin="3" end="20" step="3">
    <c:out value="${i}"/><br/>
  </c:forEach>

Results:

Now
Tue Oct 10 16:31:48 PDT 2006

Usernames
* ${usernames}

Usernames array
[matt, ceme, kid, senior]

Numbers
3
6
9
12
15
18

As you can see the <c:out> is working for the date ("Now").
The username array is in the jsp ("Username array"). Those are my four users.
The <c:forEach> isn't a completely useless tag ("Numbers").
But the <c:forEach> won't list out the usernames.

I'm using the Spring 2.0 Framework, but I don't think that matters.

Maybe I'll just be a fireman.

**whipshaw** · Oct 10th, 2006, 08:17 PM

Originally Posted by Checkerbelt

Maybe I'll just be a fireman.

lol...

I'm sorry to hear you're still stuck on this... Well, if you want to get ambitious and switch to Freemarker (that's what I use), the equivilant code would look like this:

Code:

<h2>Now</h2>
  ${now}

  <h2>Usernames</h2>
  <ul>
  <#list usernames as username>
    <li>${username}</li>
  </#list>
  </ul>

  <h2>Usernames array</h2>
  ${usernames}

  <h2>Numbers</h2>
  <#list 3..20 as i>
    ${i}"<br/>
  </#list>

Isn't that nicer, cleaner, and simpler... AND IT WILL WORK!

My company switched from JSP to FreeMarker and it was one of the best decisions we ever made...

By the way, I don't think your JSP code is wrong, you are using the forEach expression correctly. I'm thinking it is a configuration problem. You should check that you are using the latest JSTL library and schema is configured correctly.

I did a quick search and came across someone else that seemed to be having similiar problem. http://www.theserverside.com/discuss...hread_id=32113

If you still can't get it to work, switch to a cleaner, easier, faster (to code) view technology... Like FreeMarker... Trust me, you won't get these types of errors and the error messages are much nicer...

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