<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%
  long time = ... // get the file last modified or deployment time.
  response.setDateHeader("Last-Modified", time);
%>
<c:choose>
  <c:when test='${empty header["If-Modified-Since"]}'>
    <%
      System.out.println("Reponding with full content.");
    %>
  </c:when>
  <c:otherwise>
    <%
      // check the If-Modified-Since against some value...
      System.out.println("Setting not modified status");
      response.setStatus(javax.servlet.http.HttpServletResponse.SC_NOT_MODIFIED);
    %>
  </c:otherwise>
</c:choose>

# posted by rot13(Unafba Pune) @ 1:36 PM