CODEWITHSUNDEEP
javahtmljspprinting
DavideChicco.it
DavideChicco.it

Reputation: 3470

Why isn't JSP out.print() function working properly

I've been working with a JSP+Java+Html, and I've encountered a problem with out.print() function, in a for cycle. My function getGeneAvailableTaxonomies() returns a list of integer numbers (of type List<Integer>), and I want to print these numbers in an interface.

Here's my code:

 for(Integer i : ApplicationExtender.getApplicationExtender(application).getGeneAvailableTaxonomies()) 
        {
          out.print(String.format("<option value=\"%1$d\">%2$s</option>", i, TaxonId.getOrganismFromId(i)));
        }

The doce %1$d should stand for the i integer value, while %2$s should stand for the other parameter, the taxonomy id value as String.

But, unfortunately, this is what appears:

enter image description here

While I would like to see something like:

enter image description here

There's surely an error on my out.print() function call... but what's wrong?

Many thanks

Upvotes: 0

Views: 6859

Answers (3)

Harmeet Singh
Harmeet Singh

Reputation: 2616

try this as much i have understood :

        String option = "<option value=\""+d+"\">"+s+"</option>";    
        out.print(option);

using String.format

out.print(String.format("<option value=\"%d\">%s</option>", i, TaxonId.getOrganismFromId(i)));

Updated as you have mentioned in comments that TaxonID.getOrganismFromId(i) is returning int so the there is only one change in your original code %2$s to %2$d thats it...

out.print(String.format("<option value=\"%1$d\">%2$d</option>", i, TaxonId.getOrganismFromId(i)));

Upvotes: 0

davidbuzatto
davidbuzatto

Reputation: 9424

You dont need the "$" in your format String. As you may know, using scriptlets is not a good way to do Java Web Development. I think that using JSTL is far better, as you won't mix Java code with markup in your JSP's.

Edit: The printf method is not present in out object as I said earlier, since it is a JspWriter and JspWriter not inherit from PrintWriter (that have printf). Sorry. So, try this (it worked for me).

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    </head>
    <body>
        <select>
            <%
                String[] strings = new String[]{ "aaa", "bbb", "ccc", "ddd" };

                for ( int i = 0; i < strings.length; i++ ) {
                    out.print( String.format( "<option value='%d'>%s</option>", i, strings[i] ) );
                }
            %>
        </select>
    </body>
</html>

If you want to use a PrintWriter as in Servlets, so this will work:

<%@page import="java.io.PrintWriter"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    </head>
    <body>
        <select>
            <%
                PrintWriter writer = new PrintWriter( out );
                String[] strings = new String[]{ "aaa", "bbb", "ccc", "ddd" };

                for ( int i = 0; i < strings.length; i++ ) {
                    writer.printf( "<option value='%d'>%s</option>", i, strings[i] );
                }
            %>
        </select>
    </body>
</html>

Upvotes: 1

gustafc
gustafc

Reputation: 28865

Your print/format code seems OK when I run it on http://ideone.com/u8fDT. You probably just need to have the JSP recompiled (should probably happen automatically but may sometimes require server restart).

Also, mixing HTML and Java code like this is a pretty painful way to work. JSTL or a templating system like FreeMarker would make your life easier.

Upvotes: 0

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