JSP does not support El expressions. Solution

If the following content exists, it indicates servlet 2.3/jsp 1.2.
<! -- Ctype web-app Public </SP -->
"-// Sun Microsystems, Inc. // DTD web application 2.3 // en"
Http://java.sun.com/dtd/web-app_2_3.dtd>
By default, Servlet 2.3/jsp 1.2 does not support El expressions, whereas servlet 2.4/jsp 2.0 does.
If the following settings of Web. xml do not support El expressions:
<Web-app version = "2.5"
Xmlns = "http://java.sun.com/xml/ns/javaee"
Xmlns: xsi = "http://www.w3.org/2001/XMLSchema-instance"
Xsi: schemalocation = "http://java.sun.com/xml/ns/javaee
Http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd>
Solution:
1. Modify the Web. xml file to (servlet 2.4/jsp 2.0 ):
<Web-app version = "2.4"
Xmlns = "http://java.sun.com/xml/ns/javaee"
Xmlns: xsi = "http://www.w3.org/2001/XMLSchema-instance"
Xsi: schemalocation = "http://java.sun.com/xml/ns/javaee
Http://java.sun.com/xml/ns/javaee/web-app_2_4.xsd>
2. To set a JSP page to use el expressions, you must add (control a single page) to the JSP page)
<% @ Page iselignored = "false" %>
<JSP-config>
<JSP-property-group>
<URL-pattern> *. jsp </url-pattern>
<El-ignored> false </El-ignored>
</JSP-property-group>
</JSP-config>