📄 usejstl.htm
字号:
<HTML>
<HEAD>
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
<TITLE>Using the Java Standard Tag Library (JSTL) in a JSP Page (Java Developers Almanac Example)
</TITLE>
<META CONTENT="Patrick Chan" NAME="AUTHOR">
<META CONTENT="Code Examples from The Java Developers Almanac 1.4" NAME="DESCRIPTION">
<META CONTENT="Addison-Wesley/Patrick Chan" NAME="OWNER">
<META CONTENT="3/20/02" NAME="revision">
<META CONTENT="no-cache" HTTP-EQUIV="Pragma">
<LINK href="/almanac.css" media="screen" type="text/css" rel="stylesheet">
</HEAD>
<BODY>
<TABLE CELLSPACING="0" CELLPADDING="0" BORDER="0">
<TR>
<TD></TD>
</TR>
</TABLE>
<br>
<TABLE CELLSPACING="0" CELLPADDING="0" BORDER="0">
<TR>
<TD></TD>
</TR>
<TR>
<TD rowspan="3"><A HREF="/?l=ex"><IMG BORDER="0" ALIGN="BOTTOM" HSPACE="10" SRC="/egs/almanac14a.jpg"></A></TD><TD VALIGN="top">
<h1>The Java Developers Almanac 1.4</h1>
<br>
Order this book from <a href="/cgi-bin/scripts/redirect.pl?l=ex&url=http://www.amazon.com/exec/obidos/ASIN/0201752808/xeo">Amazon</a>.
</TD>
</TR>
<TR>
<TD align="right" valign="bottom">
<FORM method="get" action="/cgi-bin/search/find.pl">
<INPUT size="25" name="words" type="text"><INPUT value="Search" type="submit">
</FORM>
</TD>
</TR>
</TABLE>
<HR color="#6666cc">
<TABLE CELLSPACING="0" CELLPADDING="0" BORDER="0">
<TR>
<TD valign="top"><script type="text/javascript">
<!--
google_ad_client = "pub-6001183370374757";
google_ad_width = 120;
google_ad_height = 600;
google_ad_format = "120x600_as";
google_ad_channel = "4777242811";
google_ad_type = "text_image";
google_color_border = "FFFFFF";
google_color_bg = "FFFFFF";
google_color_link = "6666CC";
google_color_url = "6666CC";
google_color_text = "000000";
//--></script><script src="http://pagead2.googlesyndication.com/pagead/show_ads.js" type="text/javascript"></script></TD><TD> </TD><TD valign="top">
<DIV ALIGN="LEFT">
<A HREF="/">Home</A>
>
<A HREF="../index.html">List of Packages</A>
>
<B><A HREF="../javax.servlet.jsp.jstl.core/pkg.html">javax.servlet.jsp.jstl.core</A></B><font color="#666666" class="xsmall-font">
[6 examples]
</font>
</DIV><P>
<h3>e1064. 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> <%-- Copy TLD files from WSDP installation --%>
<copy todir="${build}/WEB-INF/tld">
<fileset dir="${jwsdp.home}/tools/jstl/tld">
<include name="*.tld" />
</fileset>
</copy>
<%-- Copy JSTL jar files from WSDP installation --%>
<copy todir="${build}/WEB-INF/lib">
<fileset dir="${jwsdp.home}/tools/jstl">
<include name="jstl.jar" />
</fileset>
<fileset dir="${jwsdp.home}/tools/jstl/standard/lib">
<include name="standard.jar" />
</fileset>
</copy>
</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> <%-- Core --%>
<%@ taglib uri="/WEB-INF/tld/c-rt.tld" prefix="c_rt" %>
<%-- I18N Formatting --%>
<%@ taglib uri="/WEB-INF/tld/fmt-rt.tld" prefix="fmt_rt" %>
<%-- SQL --%>
<%@ taglib uri="/WEB-INF/tld/sql-rt.tld" prefix="sql_rt" %>
<%-- XML --%>
<%@ taglib uri="/WEB-INF/tld/x-rt.tld" prefix="x_rt" %>
</pre>
The tags in the JSTL core tag library can then be referenced using the
specified prefix as in:
<pre> <c_rt:if test='<%= request.getParameter("param") != null %>'>
<%= request.getParameter("param") %>
</c_rt:if>
</pre>
See also <a href="../javax.servlet.jsp.jstl.core/uselang.html" class="eglink"><b>e1065</b> Enabling the JSTL Expression Language in a JSP Page</a>.
<P><table width="600" CELLSPACING="0" CELLPADDING="2" BORDER="0">
<tr>
<td bgcolor="#6666cc" align="center"><font color="#ffffff">
<b>Related Examples</b></font></td>
</tr>
</table>
e1065. <a class="eglink" href="uselang.html?l=rel">
Enabling the JSTL Expression Language in a JSP Page
</a>
<br>
e1066. <a class="eglink" href="getparam.html?l=rel">
Getting a Request Parameter Using JSTL in a JSP Page
</a>
<br>
e1067. <a class="eglink" href="attr.html?l=rel">
Saving Data Using JSTL in a JSP Page
</a>
<br>
e1068. <a class="eglink" href="htmlfrag.html?l=rel">
Saving and Emitting HTML Fragments Using JSTL in a JSP Page
</a>
<br>
e1069. <a class="eglink" href="if.html?l=rel">
Conditionally Generating Output Using JSTL in a JSP Page
</a>
<br>
<br>
<br>
<FONT class="xsmall-font">
© 2002 Addison-Wesley.
</FONT></TD><TD> </TD><TD valign="top"><A href="http://compositesw.com/devzone?ref=javaalmanac"><IMG alt="Click Here" height="600" width="120" border="0" src="/csw_oad_120x600_final.gif"></A></TD>
</TR>
</TABLE>
</BODY>
<HEAD>
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
<META CONTENT="NO-CACHE" HTTP-EQUIV="PRAGMA">
</HEAD>
</HTML>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -