Question

How can I display my list in a TestArea line after line with no additional spaces. i.e:

this
that
the
other

Here is my attempt:

<div class="text">
    <label for="output_string">Output:</label> `
    <textarea rows="10" cols="20">
        <c:forEach var="x" items="${messagelist}">${x}</c:forEach>
    </textarea>
</div>

Answer 1

Here’s a guess (which I’ll try out in just a sec in one of my own pages):

<c:forEach var='x' items='${messagelist}'><c:out value='${x}\r\n'/></c:forEach>

edit — no that doesn’t seem to work at all. However, what did work was for me to add a message catalog entry like this:

linebreak={0}\r\n

Then you can use <fmt:message key="linebreak"><fmt:param value="${x}"/></fmt:message> to produce the string terminated by line breaks.

Note that JSP will put spaces before the first entry according to the indentation in your .jsp source file before the <c:forEach>, so you’ll have to line everything up at the left edge if you don’t want that.

If I had to do this a lot, I’d write an EL add-on function of my own to echo back a string followed by CRLF.

edit — If you want to write an EL add-on, you need two things:

• The function itself, which should be a public static method of some class. I keep a class around called “ELFunctions” for most of mine. You can arrange them any way you want.
• A “.tld” file, if you don’t already have one. It should end up in your webapp somewhere under “WEB-INF”. Mine goes in a subdirectory called “tld”, but you can put it anywhere.

So you would write a little function like this, in some class:

public static String linebreak(final String msg) {
    return msg + "\r\n";
}

Then your “.tld” file would look like this (assuming it’s the only thing you’ve got; if you have an existing “.tld” file just add the clause):

<taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd" version="2.0">
  <description>Your Favorite Description</description>
  <display-name>Make Something Up</display-name>
  <tlib-version>4.0</tlib-version>
  <short-name>whatever</short-name>
  <uri>http://yourdomain.com/tld/whatever</uri>

  <function>
    <description>
        Return a string augmented with trailing line break (CR - LF pair)
    </description>
    <name>linebreak</name>
    <function-class>your.package.name.YourClass</function-class>
    <function-signature>
        java.lang.String linebreak(java.lang.String)
    </function-signature>
  </function>

(Boy, XML is so annoying.) Now somewhere you probably already have a little file that pulls in taglibs for your pages (for <c:...> tags at least). In there, or at the top of any page, add a line like this:

  <%@ taglib prefix="whatever" uri='http://yourdomain.com/tld/tango' %>

I think that the JSP runtime searches for “.tld” files by looking through the WEB-INF subtree, and in .jar files in WEB-INF/lib, matching by that “uri” string. Anyway, once you’ve done that, in your JSP file you can say:

  <c:forEach var='x' items='${messagelist}'>${whatever:linebreak(x)}</c:forEach>

and it’ll invoke your function.