Spring MVC and JSTL

[stimpy]

I hope this is the correct forum for this question.


I have a simple Spring MVC based web app.

I generate a ArrayList of Hash Maps which look like this

[{key1=value1, key2=value2, key3=value3, key4=value4}, {key1=value1, key2=value2, key3=value3, key4=value4}]

I use a multi action controller to return this object with my view like this

 ModelAndView view = new ModelAndView("list_view");
        view.addObject("list", ListObject);
        return view ;

in my view

     <TABLE BORDER="1">
      <TH>Test</TH>
      <c:forEach var="current_outer" items="${Request.list}">
                <c:forEach var="current_inner" items="${current_outer}">
        <TR>
          <TD><c:out value="${current_inner.Key1}"  /></TD>
          <TD><c:out value="${current_inner.Key2}"  /></TD>
          <TD><c:out value="${current_inner.Key3}"  /></TD>
          <TD><c:out value="${current_inner.Key4}"  /></TD>
        </TR>
              </c:forEach>
      </c:forEach>
    </TABLE>

Everything compiles and loads fine into tomcat . I have verified that JSTL is work correctly in tomcat. I have verified that the request contains all the right values .

However I get no data rendering in the table rows .

I suspect I am not correctly referencing the object to the JSTL forEach tag.

I thought a had an iterations problem thus the outer and inner forEach loops. but even with only one forEach i get the same result

<tbody><tr><th>Test</th>
      </tr><tr>
          <td><c:out value=""></c:out></td>
          <td><c:out value=""></c:out></td>
          <td><c:out value=""></c:out></td>
          <td><c:out value=""></c:out></td>
        </tr>
           
    </tbody>

google,books and the petclinic have all failed me at this point

any help would be greatly appreciated.

[jamestastic]

Try the following:

• Change "Request.list" to "list"
• Change "current_inner.Key1" to "current_inner.key" and "current_inner.value"

<TABLE BORDER="1">
  <TH>Test</TH>
  <c:forEach var="current_outer" items="${Request.list}">
    <c:forEach var="current_inner" items="${current_outer}">
      <TR>
        <TD><c:out value="${current_inner.key}"  />: <c:out value="${current_inner.value}"  /></TD>
      </TR>
    </c:forEach>
  </c:forEach>
</TABLE>

[stimpy]

Ok i will give that a try .

Thanks for the quick response . I tried some variations on the values options earlier but not this one .

I also used the "list" option as well but will try again . When i used the "list" object I expected to see x number of TR blocks , one for each list element even if the values were not there . I never reached that error state , always only 4.

I will try what you suggest and post back.

thanks again

[stimpy]

Ok Well we have change and thats good .

I now get an exception ( non was thrown previously ) when the jsp loads.

org.apache.jasper.JasperException: An exception occurred processing JSP page /WEB-INF/views/list.jsp at line 51

48: <c:forEach var="current_outer" items="${List}">
49: <c:forEach var="current_inner" items="${current_outer}">
50: <TR>
51: <TD><c:out value="${current_inner.Key1}"/></TD><TD><c:out value="${current_inner.value}"/></TD>
52: <TD><c:out value="${current_inner.Key2}"/></TD><TD><c:out value="${current_inner.value}"/></TD>
53: <TD><c:out value="${current_inner.Key3}"/></TD><TD><c:out value="${current_inner.value}"/></TD>
54: <TD><c:out value="${current_inner.Key4}"/></TD><TD><c:out value="${current_inner.value}"/></TD>

javax.el.PropertyNotFoundException: Property 'Key1' not found on type java.util.HashMap$Entry

I double checked the key names ( including case) and they are correct.

Perhaps its looking on the wrong block or location?

hmmm

[jamestastic]

current_inner is of type HashMap$Entry. This means you can reference its "key" and "value" properties to get the key and value of a given entry.

Change your code to use current_inner.key rather than current_inner.Key1:

<c:out value="${current_inner.key}"/>

This will output the key itself.

[stimpy]

That did it .

Thanks very much .

As a side note where can find the JSTL docs ?

i could only find the 1.1 docs here

http://download.oracle.com/docs/cd/E.../docs/tlddocs/

[stimpy]

Ok expanding of the reference question above .

It appears the in the c:out tag is an EL expression. ( right ? )

The question is how do i get the value based on key ?

something like

          <TD><c:out value="${current_inner.["literalNameOfKey"].value}"/></TD>

do i have do something awkward like

<c:choose>
<c:when test="${current_inner.key == literalNameOfKey}">
<TD><c:out value="${current_inner.value}"/></TD>
</c:when> 
</c:choose>

I don think the above will produce the results desired ..ie values based on a specific key where needed.