title: jakarta.servlet.ServletException: java.lang.NoClassDefFoundError: javax/servlet/jsp/tagext/TagLibraryValidator
body: <p>I am trying to execute JSP with JSTL, but I am not able to. I have Apache Tomcat 10, i.e. <code>jakarta.servlet.*</code> instead of <code>javax.servlet.*</code>. So whenever I execute the web app with JSTL 1.2.5 files, then I get the error:</p>
  <pre><code>jakarta.servlet.ServletException: java.lang.NoClassDefFoundError: javax/servlet/jsp/tagext/TagLibraryValidator
      at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
      at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:778)
      at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
  </code></pre>
  <p>I tried to find a similar problem/question online that is resolved, but was not able to find it. How can I use JSTL in JSP with Tomcat 10?</p>
  <p>My index JSP file code:</p>
  <pre><code>&lt;%@ taglib uri=&quot;http://java.sun.com/jsp/jstl/core&quot; prefix=&quot;c&quot; %&gt; 
  &lt;html&gt;  
    &lt;head&gt;  
      &lt;title&gt;Tag Example&lt;/title&gt;  
    &lt;/head&gt;  
    &lt;body&gt;  
      &lt;c:out value=&quot;${'Hello Yo'}&quot;/&gt; 
    &lt;/body&gt;  
  &lt;/html&gt;  
  </code></pre>