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<TITLE>Using the Java Standard Tag Library (JSTL) in a JSP Page
(Java Developers Almanac Example)
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<META CONTENT="Patrick Chan" NAME="AUTHOR">
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    <B><A HREF="../javax.servlet.jsp.jstl.core/pkg.html">javax.servlet.jsp.jstl.core</A></B><font color="#666666" SIZE="-2">
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  <h3>
    e1063.  
    Using the Java Standard Tag Library (JSTL) in a JSP Page</h3>

There are four tag libraries that make up the JSTL; see the
<code>javax.servlet.jsp.jstl.*</code> packages for examples that use these tag
libraries.  JSTL is not yet a standard part of a JSP container.
Hence, in order to use the JSTL in a web application, you must include
a copy the JSTL library code in the WEB-INF directory of your web
application. These files are available in the Web Services Developer
Pack, which can be download from
<code>http://java.sun.com/webservices/webservicespack.html</code>.  

<P> A tag library has two parts - a Tag Library Descriptor (TLD)
file and a JAR file. The following ant elements copy the TLD files
from the Web Services Developer Pack into <code>WEB-INF/tld</code> and the JAR
files into <code>WEB-INF/lib</code>.  These elements should be added to the
build target in your build.xml file:


<pre>
    &lt;%-- Copy TLD files from WSDP installation --%&gt;
    &lt;copy todir="${build}/WEB-INF/tld"&gt;
      &lt;fileset dir="${jwsdp.home}/tools/jstl/tld"&gt;
        &lt;include name="*.tld" /&gt;
      &lt;/fileset&gt;
    &lt;/copy&gt;
    
    &lt;%-- Copy JSTL jar files from WSDP installation --%&gt;
    &lt;copy todir="${build}/WEB-INF/lib"&gt;
      &lt;fileset dir="${jwsdp.home}/tools/jstl"&gt;
        &lt;include name="jstl.jar" /&gt;
      &lt;/fileset&gt;
      &lt;fileset dir="${jwsdp.home}/tools/jstl/standard/lib"&gt;
        &lt;include name="standard.jar" /&gt;
      &lt;/fileset&gt;
    &lt;/copy&gt;
</pre>
In order for a JSP page to use the JSTL, it must declare it's
use on the page using the <code>taglib</code> directive.  Here's an example
that declares the use of all four JSTL tag libraries:


<pre>
    &lt;%-- Core --%&gt;
    &lt;%@ taglib uri="/WEB-INF/tld/c-rt.tld" prefix="c_rt" %&gt;
    
    &lt;%-- I18N Formatting --%&gt;
    &lt;%@ taglib uri="/WEB-INF/tld/fmt-rt.tld" prefix="fmt_rt" %&gt;
    
    &lt;%-- SQL --%&gt;
    &lt;%@ taglib uri="/WEB-INF/tld/sql-rt.tld" prefix="sql_rt" %&gt;
    
    &lt;%-- XML --%&gt;
    &lt;%@ taglib uri="/WEB-INF/tld/x-rt.tld" prefix="x_rt" %&gt;
</pre>

The tags in the JSTL core tag library can then be referenced using the
specified prefix as in:


<pre>
    &lt;c_rt:if test='&lt;%= request.getParameter("param") != null %&gt;'&gt;
        &lt;%= request.getParameter("param") %&gt;
    &lt;/c_rt:if&gt;
</pre>
See also <a href="../javax.servlet.jsp.jstl.core/uselang.html" class="eglink"><font size="-1"><b>e1064</b> Enabling the JSTL Expression Language in a JSP Page</font></a>.

<P><table width="600" CELLSPACING="0" CELLPADDING="2" BORDER="0">
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            &nbsp;Related Examples
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e1064. <a class="eglink" href="uselang.html?l=rel">
    Enabling the JSTL Expression Language in a JSP Page
</a>
<br>

e1065. <a class="eglink" href="getparam.html?l=rel">
    Getting a Request Parameter Using JSTL in a JSP Page
</a>
<br>

e1066. <a class="eglink" href="attr.html?l=rel">
    Saving Data Using JSTL in a JSP Page
</a>
<br>

e1067. <a class="eglink" href="htmlfrag.html?l=rel">
    Saving and Emitting HTML Fragments Using JSTL in a JSP Page
</a>
<br>

e1068. <a class="eglink" href="if.html?l=rel">
    Conditionally Generating Output Using JSTL in a JSP Page
</a>
<br>


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