Hello and thank you for reading this question:
I am learning web development and design patterns with Java and I would like to learn how to use JSLT tags. The reason is because of they are easier to read and are the recommended approach, as here is being said: How to avoid Java code in JSP files?
I would like to replace this working servlet:
<%--
Document : Cuestionario
Created on : 10-feb-2018, 9:36:15
Author : YonePC
--%>
<%@page import="org.Cuestionario"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
</head>
<body>
<% Cuestionario cuestionario = (Cuestionario) session.getAttribute("cuestionario");%>
<h1><%= cuestionario.getPregunta1()%></h1>
<form>
<div style="display:flex">
<h2><%= cuestionario.getRespuestaTexto11()%></h2>
<input type="checkbox" name="respuestaVerdad11" value="<%= cuestionario.getRespuestaVerdad11()%>" />
<h2><%= cuestionario.getRespuestaTexto12()%></h2>
<input type="checkbox" name="respuestaVerdad11" value="<%= cuestionario.getRespuestaVerdad12()%>" />
<h2><%= cuestionario.getRespuestaTexto13()%></h2>
<input type="checkbox" name="respuestaVerdad11" value="<%= cuestionario.getRespuestaVerdad13()%>" />
</div>
<input type="reset" value="Enviar respuesta" />
</form>
</body>
</html>
To be able to use JSLT tags. I have followed the JSLT's wiki's steps: https://stackoverflow.com/tags/jstl/info
However when I try the following little example:
<%--
Document : Cuestionario
Created on : 10-feb-2018, 9:36:15
Author : YonePC
--%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@page import="org.Cuestionario"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
</head>
<body>
<c:set var="cuestionario" value="${session.getAttribute(\"cuestionario\")}"></c:set>
<c:out value="${cuestionario}"></c:out>
<% Cuestionario cuestionario = (Cuestionario) session.getAttribute("cuestionario");%>
<h1><%= cuestionario.getPregunta1()%></h1>
<form>
<div style="display:flex">
<h2><%= cuestionario.getRespuestaTexto11()%></h2>
<input type="checkbox" name="respuestaVerdad11" value="<%= cuestionario.getRespuestaVerdad11()%>" />
<h2><%= cuestionario.getRespuestaTexto12()%></h2>
<input type="checkbox" name="respuestaVerdad11" value="<%= cuestionario.getRespuestaVerdad12()%>" />
<h2><%= cuestionario.getRespuestaTexto13()%></h2>
<input type="checkbox" name="respuestaVerdad11" value="<%= cuestionario.getRespuestaVerdad13()%>" />
</div>
<input type="reset" value="Enviar respuesta" />
</form>
</body>
</html>
Which tries to declare a variable and print it, the JSP page is white.
I have also read to fix this issue by myself: Set request attribute using JSTL
What are all the escape characters?
https://docs.oracle.com/cd/E13222_01/wls/docs92/webapp/configureservlet.html
And I have understood the tag's meaning with: https://www.journaldev.com/2090/jstl-tutorial-jstl-tags-example
Could you help me, please?
As a note I write the web.xml I included under WEB-INF:
<?xml version="1.0" encoding="UTF-8"?>
<web-app
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"
version="2.5">
</web-app>
Also I included the .jar both under the NetBean's project's libraries and under /WEB-INF/lib folder.
In addition the app's architecture is:
Thank you for your help.
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