title: The attribute prefix fn does not correspond to any imported tag library
body: <p>I try to run my jsp code on Tomcat v7 server but it failed.</p>
  
  <p>org.apache.jasper.JasperException: /jsp/Checkout.jspx (line: 32, column: 51) The attribute prefix fn does not correspond to any imported tag library</p>
  
  <p>But my jsp code had fn definition</p>
  
  <p>xmlns:fn="http://java.sun.com/jsp/jstl/functions" </p>
  
  <p>My jsp code : Checkout.jspx</p>
  
  <pre><code>    &lt;?xml version="1.0" encoding="UTF-8"?&gt;
      &lt;jsp:root
       xmlns:jsp="http://java.sun.com/JSP/Page"
       xmlns:c="http://java.sun.com/jsp/jstl/core"
       xmlns:fn="http://java.sun.com/jsp/jstl/functions" 
       xmlns:eshop="urn:jsptld:/WEB-INF/tlds/eshop.tld"
       version="2.1"
       &gt;
      &lt;jsp:directive.page
       language="java"
       contentType="application/xhtml+xml;charset=UTF-8"
       /&gt;
  &lt;jsp:output omit-xml-declaration="false"/&gt;
  &lt;jsp:output
    doctype-root-element="html"
    doctype-public="-//W3C//DTD XHTML 1.0 Strict//EN"
    doctype-system="http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"
    /&gt;
  &lt;c:url var="cssUrl" value="/css/eshop.jspx"/&gt;
  
  &lt;html xmlns="http://www.w3.org/1999/xhtml"&gt;
  &lt;head&gt;
    &lt;title&gt;Check Out&lt;/title&gt;
    &lt;link rel="stylesheet" href="${cssUrl}" type="text/css"/&gt;
    &lt;/head&gt;
  &lt;body&gt;
  &lt;jsp:include page="TopMenu.jspx" flush="true"/&gt;
  &lt;jsp:include page="LeftMenu.jspx" flush="true"/&gt;
  &lt;div class="content"&gt;
    &lt;h2&gt;CheckOut&lt;/h2&gt;
    &lt;c:choose&gt;
      &lt;c:when test="${fn:length(shoppingCart) &gt; 0}"&gt;
        &lt;form action=""&gt;
          &lt;input type="hidden" name="action" value="orderConfirmation"/&gt;
          &lt;table class="checkout"&gt;
            &lt;tr&gt;
              &lt;th colspan="2"&gt;Delivery Details&lt;/th&gt;
              &lt;/tr&gt;
            &lt;tr&gt;
              &lt;td&gt;Contact Name:&lt;/td&gt;
              &lt;td&gt;&lt;input type="text" name="contactName"/&gt;&lt;/td&gt;
              &lt;/tr&gt;
            &lt;tr&gt;
              &lt;td&gt;Delivery Address:&lt;/td&gt;
              &lt;td&gt;&lt;input type="text" name="deliveryAddress"/&gt;&lt;/td&gt;
              &lt;/tr&gt;
            &lt;tr&gt;
              &lt;th colspan="2"&gt;Credit Card Details&lt;/th&gt;
              &lt;/tr&gt;
            &lt;tr&gt;
              &lt;td&gt;Name on Credit Card:&lt;/td&gt;
              &lt;td&gt;&lt;input type="text" name="ccName"/&gt;&lt;/td&gt;
              &lt;/tr&gt;
            &lt;tr&gt;
              &lt;td&gt;Credit Card Number:&lt;/td&gt;
              &lt;td&gt;&lt;input type="text" name="ccNumber"/&gt;&lt;/td&gt;
              &lt;/tr&gt;
            &lt;tr&gt;
              &lt;td&gt;Credit Card Expiry Date:&lt;/td&gt;
              &lt;td&gt;&lt;input type="text" name="ccExpiryDate"/&gt;&lt;/td&gt;
              &lt;/tr&gt;
            &lt;tr&gt;
              &lt;td&gt;&lt;/td&gt;
              &lt;td&gt;&lt;input type="submit" value="Confirm Order"/&gt;&lt;/td&gt;
              &lt;/tr&gt;
            &lt;/table&gt;
          &lt;/form&gt;
        &lt;/c:when&gt;
      &lt;c:otherwise&gt;
        &lt;p class="error"&gt;ERROR: You can't check out an empty shopping cart!&lt;/p&gt;
        &lt;/c:otherwise&gt;
      &lt;/c:choose&gt;
    &lt;/div&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  &lt;/jsp:root&gt;
  </code></pre>
  
  <p>Web.xml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:javaee="http://java.sun.com/xml/ns/javaee"
      xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee;http://java.sun.com/xml/ns/j2ee/web-app_2_5.xsd"
      id="WebApp_ID" version="2.5"&gt;
  
  
      &lt;display-name&gt;eshop&lt;/display-name&gt;
      &lt;servlet&gt;
          &lt;description&gt;
          &lt;/description&gt;
          &lt;display-name&gt;ShopServlet&lt;/display-name&gt;
          &lt;servlet-name&gt;ShopServlet&lt;/servlet-name&gt;
          &lt;servlet-class&gt;eshop.ShopServlet&lt;/servlet-class&gt;
          &lt;init-param&gt;
              &lt;param-name&gt;base&lt;/param-name&gt;
              &lt;param-value&gt;/shop&lt;/param-value&gt;
          &lt;/init-param&gt;
          &lt;init-param&gt;
              &lt;param-name&gt;imageURL&lt;/param-name&gt;
              &lt;param-value&gt;/images/&lt;/param-value&gt;
          &lt;/init-param&gt;
          &lt;init-param&gt;
              &lt;param-name&gt;jdbcDriver&lt;/param-name&gt;
              &lt;param-value&gt;com.mysql.jdbc.Driver&lt;/param-value&gt;
          &lt;/init-param&gt;
          &lt;init-param&gt;
              &lt;param-name&gt;dbURL&lt;/param-name&gt;
              &lt;param-value&gt;jdbc:mysql://localhost:3306/shop&lt;/param-value&gt;
          &lt;/init-param&gt;
          &lt;init-param&gt;
              &lt;param-name&gt;dbUserName&lt;/param-name&gt;
              &lt;param-value&gt;root&lt;/param-value&gt;
          &lt;/init-param&gt;
          &lt;init-param&gt;
              &lt;param-name&gt;dbPassword&lt;/param-name&gt;
              &lt;param-value&gt;&lt;/param-value&gt;
          &lt;/init-param&gt;
      &lt;/servlet&gt;
      &lt;servlet-mapping&gt;
          &lt;servlet-name&gt;ShopServlet&lt;/servlet-name&gt;
          &lt;url-pattern&gt;/shop/*&lt;/url-pattern&gt;
      &lt;/servlet-mapping&gt;
      &lt;session-config&gt;
          &lt;tracking-mode&gt;COOKIE&lt;/tracking-mode&gt;
      &lt;/session-config&gt;
       &lt;/web-app&gt;
  </code></pre>
  
  <p>How should I solve this problem?</p>
  
  <p>I loaded the project again in eclipse, I just changed the code in web.xml.</p>
  
  <pre><code>servlet-mapping&gt;
  &lt;servlet-name&gt;ShopServlet&lt;/servlet-name&gt;
  &lt;url-pattern&gt;/ShopServlet&lt;/url-pattern&gt;
  &lt;/servlet-mapping&gt; 
  </code></pre>
  
  <p>URL is : localhost:8080/eshopx/ShopServlet</p>
  
  <p>The error message changed</p>
  
  <p>description The requested resource is not available.  </p>