Assign a java object file value into jsp variable

Question

The following is part of my jsp code:

${cForm.cId} <!-- I can see this value displayed correctly --%>
    <%! String i = ${cForm.cId}; %> 
    <td class="value">
        <img src="/supportcenter/cServlet?sampleImg=<%=i %>" width="300px" />
    </td>

cForm is my java object file, I can see the value displayed correctly in browser for the ${cForm.cId}.

However, when I want to assign the value into String i variable, I keep hit failed to compile : jsp error.

Kindly advise.

try this,not sure if it will work `<%! String i = (String)${cForm.cId}; %> ` — Santino 'Sonny' Corleone, May 12 '14 at 04:31

score 5 · Accepted Answer · edited May 23 '17 at 11:50

You cannot mix expression language inside scriptlet. You should use scriptlet only or expression language only.

To fix your current error, retrieve the attribute from request (or wherever it is stored):

<% String i = ((CForm)request.getAttribute("cForm")).getId(); %>

To really solve your problem: stop using scriplets at all, keep it all in expression language:

<img src="/supportcenter/cServlet?sampleImg=${cForm.cId}" width="300px" />

Keerthivasan · Answer 2 · 2014-05-12T04:38:24.967

2

When you write a scriptlet, it just expects Java programming language. so, you should't put EL in it. You can assign the value to a page scoped attribute and get it in the scriptlet

 <c:set var="cFormId" value=${cForm.cId}/>
 <%
    String i = (String)pageContext.getAttribute("cFormId");   
  %>

Note : Usage of Scriptlets is a bad practice. To solve your problem, just create the URL making use of EL value directly without beating around the bush

<img src="/supportcenter/cServlet?sampleImg=${cForm.cId}" width="300px" />

edited May 12 '14 at 04:38

answered May 12 '14 at 04:33

Keerthivasan

12,760
2
32
53

That's not JSTL, it is expression language. – Luiggi Mendoza May 12 '14 at 04:37
@LuiggiMendoza Thank you, Corrected. I get confused often with these two :) – Keerthivasan May 12 '14 at 04:38
Expression language is that stuff between `${...}`. JSTL is a jsp tag library which gives you great functionalities for JSP like ``, ``, ``, etc. – Luiggi Mendoza May 12 '14 at 04:40
@LuiggiMendoza Yeah,I can understand. Thanks for explaining the concepts behind them. – Keerthivasan May 12 '14 at 04:41
I always think that I am getting good in Java. But, it always proves me that I'm not :) – Keerthivasan May 12 '14 at 04:44
Happens to everybody, my friend :). – Luiggi Mendoza May 12 '14 at 04:45
Ha ha, really. I definitely believe that one day I will become a good programmer. Anyway, You are a very good person to meet around here. Keep up your good work. – Keerthivasan May 12 '14 at 04:51

score 1 · Answer 3 · answered May 12 '14 at 04:38

1

you may try this if you simply want to append in the url without extra variable:

<td class="value">
  <img src="/supportcenter/cServlet?sampleImg=${cForm.cId}" width="300px" />
</td>

answered May 12 '14 at 04:38

score 0 · Answer 4 · answered May 12 '14 at 04:32

0

That is because the <% indicates the start of Java code (a scriptlet).

The ${...} notation (expression language) can't be used inside <% ... %> tags.

answered May 12 '14 at 04:32

Jason

11,744
3
42
46

Assign a java object file value into jsp variable

4 Answers4

Linked

Related