CODEWITHSUNDEEP
jsptomcatwhitespace
Seth Weiner
Seth Weiner

Reputation: 3019

Strip whitespace from jsp output

How can I strip out extra whitespace from jsp pages' output? Is there a switch I can flip on my web.xml? Is there a Tomcat specific setting?

Upvotes: 119

Views: 96679

Answers (10)

PRAVENDRA S KHINCHI B16EE026
PRAVENDRA S KHINCHI B16EE026

Reputation: 131

In web.xml add this servlet this trim param

<servlet>
                <servlet-name>jsp</servlet-name>
                <servlet-class>org.apache.jasper.servlet.JspServlet</servlet-class>
                <init-param>
                    <param-name>fork</param-name>
                    <param-value>false</param-value>
                </init-param>
                <init-param>
                    <param-name>xpoweredBy</param-name>
                    <param-value>false</param-value>
                </init-param>
                <init-param>
                    <param-name>trimSpaces</param-name>
                    <param-value>true</param-value>
                </init-param>
                <load-on-startup>3</load-on-startup>
            </servlet>
            <servlet-mapping>
                <servlet-name>default</servlet-name>
                <url-pattern>/</url-pattern>
            </servlet-mapping>

            <!-- The mappings for the JSP servlet -->
            <servlet-mapping>
                <servlet-name>jsp</servlet-name>
                <url-pattern>*.jsp</url-pattern>
                <url-pattern>*.jspx</url-pattern>
            </servlet-mapping>

Upvotes: 0

Ghostff
Ghostff

Reputation: 1458

Just a bit off the actual question, If you want to get rid of the empty lines cause by whatever you did before outputting, you can use

out.clearBuffer();

Upvotes: 0

Jorge Santos Neill
Jorge Santos Neill

Reputation: 1785

Please, use the trim funcion, example

fn:trim(string1)

Upvotes: 1

Simon B
Simon B

Reputation: 1844

The trimDirectiveWhitespaces is only supported by servlet containers that support JSP 2.1 and after, or in the case or Tomcat, Tomcat 6 (and some versions e.g. Tomcat 6.0.10 don't implement it properly - don't know about the others). There's more information about trimDirectiveWhitespaces here:

http://www.oracle.com/technetwork/articles/javaee/jsp-21-136414.html

and here

http://raibledesigns.com/rd/entry/trim_spaces_in_your_jsp1

Upvotes: 5

Andres
Andres

Reputation: 1146

If you're using tags, you can apply there too:

<%@ tag description="My Tag" trimDirectiveWhitespaces="true" %>

And on your jsp:

<%@ page trimDirectiveWhitespaces="true" %>

Upvotes: 5

yglodt
yglodt

Reputation: 14551

You can go one step further and also remove newlines (carriage returns) between the html tags at build time.

E.g. change:

<p>Hello</p>
<p>How are you?</p>

into:

<p>Hello</p><p>How are you?</p>

Do do that, use the maven-replacer-plugin and set it up in pom.xml:

<plugin>
    <groupId>com.google.code.maven-replacer-plugin</groupId>
    <artifactId>replacer</artifactId>
    <version>1.5.3</version>
    <executions>
        <execution>
            <id>stripNewlines</id>
            <phase>prepare-package</phase>
            <goals>
                <goal>replace</goal>
            </goals>
            <configuration>
                <basedir>${project.build.directory}</basedir>
                <filesToInclude>projectname/WEB-INF/jsp/**/*.jsp</filesToInclude>
                <token>&gt;\s*&lt;</token>
                <value>&gt;&lt;</value>
                <regexFlags>
                    <regexFlag>MULTILINE</regexFlag>
                </regexFlags>
            </configuration>
        </execution>
    </executions>
</plugin>

This will only modify the JSPs in the build-directory, and not touch the JSPs in your sources.

You might need to adapt the path (<filesToInclude>) where your JSPs are located in.

Upvotes: 1

Rajkumar Rajadurai
Rajkumar Rajadurai

Reputation: 1

Add/edit your tomcat catalina.properties file with 

org.apache.jasper.compiler.Parser.STRICT_QUOTE_ESCAPING=false

See also: https://confluence.sakaiproject.org/display/BOOT/Install+Tomcat+7

Upvotes: 0

Rontologist
Rontologist

Reputation: 3558

There is a trimWhiteSpaces directive that should accomplish this,

In your JSP:

<%@ page trimDirectiveWhitespaces="true" %>

Or in the jsp-config section your web.xml (Note that this works starting from servlet specification 2.5.):

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

Unfortunately if you have a required space it might also need strip that, so you may need a non-breaking space in some locations.

Upvotes: 182

redolent
redolent

Reputation: 4259

Not directly what you're asking for, but what helps me is putting HTML comment tags in a clever way around my jsp tags, and also putting whitespace inside a servlet tag (<% %>):

${"<!--"}
<c:if test="${first}">
    <c:set var="extraClass" value="${extraClass} firstRadio"/>
</c:if>
<c:set var="first" value="${false}"/>
${"-->"}<%

%><input type="radio" id="input1" name="dayChooser" value="Tuesday"/><%
%><label for="input1" class="${extraClass}">Tuesday</label>

Upvotes: 4

BalusC
BalusC

Reputation: 1109645

If your servletcontainer doesn't support the JSP 2.1 trimDirectiveWhitespaces property, then you need to consult its JspServlet documentation for any initialization parameters. In for example Tomcat, you can configure it as well by setting trimSpaces init-param to true in for JspServlet in Tomcat's /conf/web.xml:

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

A completely different alternative is the JTidyFilter. It not only trims whitespace, but it also formats HTML in a correct indentation.

Upvotes: 28

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