taglibs and variable declarations generate empty lines at the top of source page

StackOverflow https://stackoverflow.com/questions/20099904

Question

I have declared some taglibs and variables in my jsp page as below:

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>

<c:set var="site" scope="session" value="${site}"/>
<c:set var="thumb" scope="session" value="${thumbnail}"/>
<c:set var="geoCode" scope="session" value="${geoCode}"/>
...
<fmt:setLocale value="${local}" />
<fmt:setBundle basename="MessagesBundle" />
<!DOCTYPE html>
<head>
    <meta charset="utf-8">
...

when I run the app and then view the source I see blank new lines on top of the source page:

.







<!DOCTYPE html>
<head>
    <meta charset="utf-8">

I just placed a dot to demonstrate the empty lines. Any idea on how I can remove these empty lines?

Was it helpful?

Solution

You need to tell the JSP servlet to trim directive whitespaces. You can achieve that by adding the following entry to webapp's web.xml:

<jsp-config>
    <jsp-property-group>
        <url-pattern>*.jsp</url-pattern>
        <trim-directive-whitespaces>true</trim-directive-whitespaces>
     </jsp-property-group>
</jsp-config>

Or, if you'd like to configure it server-wide instead of on a per-webapp basis, then consult the servletcontainer documentation on the matter. You didn't tell which one you're using, but in case of Tomcat, it'd be a matter of editing its /conf/web.xml to add the following entry to the <servlet> declaration of the JSP servlet:

<init-param>
    <param-name>trimSpaces</param-name>
    <param-value>true</param-value>
</init-param>

Unrelated to the concrete problem, your @page contains a lot of default and repeated mess. It can be simplified as follows:

<%@page pageEncoding="UTF-8"%>
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