JSP 标准标签库（JSTL）

Apache Tomcat安装JSTL 库步骤如下：

从Apache的标准标签库中下载的二进包(jakarta-taglibs-standard-current.zip)。官网下载地址

下载 jakarta-taglibs-standard-1.1.2.zip 包并解压，将 jakarta-taglibs-standard-1.1.2/lib/ 下的两个 jar 文件：standard.jar 和 jstl.jar 文件拷贝到 /WEB-INF/lib/ 下。

再将 tld 下的需要引入的 tld 文件复制到 WEB-INF 目录下。

接下来我们在 web.xml 文件中添加以下配置：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" 
    xmlns="http://java.sun.com/xml/ns/j2ee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
        http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
    <jsp-config>
    <taglib>
    <taglib-uri>http://java.sun.com/jsp/jstl/fmt</taglib-uri>
    <taglib-location>/WEB-INF/fmt.tld</taglib-location>
    </taglib>
    <taglib>
    <taglib-uri>http://java.sun.com/jsp/jstl/fmt-rt</taglib-uri>
    <taglib-location>/WEB-INF/fmt-rt.tld</taglib-location>
    </taglib>
    <taglib>
    <taglib-uri>http://java.sun.com/jsp/jstl/core</taglib-uri>
    <taglib-location>/WEB-INF/c.tld</taglib-location>
    </taglib>
    <taglib>
    <taglib-uri>http://java.sun.com/jsp/jstl/core-rt</taglib-uri>
    <taglib-location>/WEB-INF/c-rt.tld</taglib-location>
    </taglib>
    <taglib>
    <taglib-uri>http://java.sun.com/jsp/jstl/sql</taglib-uri>
    <taglib-location>/WEB-INF/sql.tld</taglib-location>
    </taglib>
    <taglib>
    <taglib-uri>http://java.sun.com/jsp/jstl/sql-rt</taglib-uri>
    <taglib-location>/WEB-INF/sql-rt.tld</taglib-location>
    </taglib>
    <taglib>
    <taglib-uri>http://java.sun.com/jsp/jstl/x</taglib-uri>
    <taglib-location>/WEB-INF/x.tld</taglib-location>
    </taglib>
    <taglib>
    <taglib-uri>http://java.sun.com/jsp/jstl/x-rt</taglib-uri>
    <taglib-location>/WEB-INF/x-rt.tld</taglib-location>
    </taglib>
    </jsp-config>
</web-app>

准备工作完成。