Caelum 11.14 Can not find the tag library descriptor for "http://java.sun.com/jsp/jstl/ core"

Front-end
#1

Prezados, boa noite.

Saberiam me dizer o que pode estar ocorrendo?
Estou seguindo a apostila da Caelum Java-Web fj-21, fazendo o exercício 11.14.
Tentei acessar a URL: http://localhost:8080/fj21-tarefas/listaTarefas
Obtive a seguinte mensagem de erro:

[code]type Exception report

message The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application
org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:56)
org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:445)
org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:117)
org.apache.jasper.compiler.TagLibraryInfoImpl.generateTLDLocation(TagLibraryInfoImpl.java:325)
org.apache.jasper.compiler.TagLibraryInfoImpl.(TagLibraryInfoImpl.java:154)
org.apache.jasper.compiler.Parser.parseTaglibDirective(Parser.java:410)
org.apache.jasper.compiler.Parser.parseDirective(Parser.java:475)
org.apache.jasper.compiler.Parser.parseElements(Parser.java:1427)
org.apache.jasper.compiler.Parser.parse(Parser.java:138)
org.apache.jasper.compiler.ParserController.doParse(ParserController.java:242)
org.apache.jasper.compiler.ParserController.parse(ParserController.java:102)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:198)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:373)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:353)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:340)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:657)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:357)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:238)
org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:264)
org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1201)
org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:986)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:933)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:851)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:953)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:844)
javax.servlet.http.HttpServlet.service(HttpServlet.java:620)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:829)
javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.53 logs.[/code]

Quando visualizei meu arquivo lista.jsp, as linhas abaixo estavam grifadas em vermelho apresentando os erros (Can not find the tag library descriptor for “http://java.sun.com/jsp/jstl/core” e Can not find the tag library descriptor for “http://java.sun.com/jsp/jstl/ fmt”):

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>

Abaixo seguem meus arquivos:
TarefasController.java

package br.com.caelum.tarefas.controller;

import javax.validation.Valid;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.RequestMapping;

import br.com.caelum.tarefas.dao.JdbcTarefaDao;
import br.com.caelum.tarefas.modelo.Tarefa;

@Controller
public class TarefasController 
{
	@RequestMapping("novaTarefa")
	public String form(){
		return "tarefa/formulario";
	}
	
	@RequestMapping("adicionaTarefa")
	public String adiciona(@Valid Tarefa tarefa, BindingResult result)
	{
		
		if(result.hasFieldErrors("descricao")){
			return "tarefa/formulario";
		}
		
		JdbcTarefaDao dao = new JdbcTarefaDao();
		dao.adiciona(tarefa);			
		return "tarefa/adicionada";
	}
	
	@RequestMapping("listaTarefas")
	public String lista(Model model)
	{
		JdbcTarefaDao dao = new JdbcTarefaDao();
		model.addAttribute("tarefas", dao.lista());
		return "tarefa/lista";
	}
	
}

Tarefa.java:

package br.com.caelum.tarefas.modelo;

import java.util.Calendar;

import javax.validation.constraints.Size;

import com.sun.istack.internal.NotNull;

public class Tarefa 
{
	private Long id;
	
	@NotNull//(message="{tarefa.descricao.vazia}") 
	@Size(min=5, message="{tarefa.descricao.pequena}")
	private String descricao;
	private boolean finalizado;
	private Calendar dataFinalizacao;
	public Long getId() {
		return id;
	}
	public void setId(Long id) {
		this.id = id;
	}
	public String getDescricao() {
		return descricao;
	}
	public void setDescricao(String descricao) {
		this.descricao = descricao;
	}
	public boolean isFinalizado() {
		return finalizado;
	}
	public void setFinalizado(boolean finalizado) {
		this.finalizado = finalizado;
	}
	public Calendar getDataFinalizacao() {
		return dataFinalizacao;
	}
	public void setDataFinalizacao(Calendar dataFinalizacao) {
		this.dataFinalizacao = dataFinalizacao;
	}
	
}

JdbcTarefaDao.java:

package br.com.caelum.tarefas.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;

import br.com.caelum.tarefas.jdbc.ConnectionFactory;
import br.com.caelum.tarefas.modelo.Tarefa;

public class JdbcTarefaDao {
	private Connection connection; 

	public JdbcTarefaDao()
	{
		this.connection = new ConnectionFactory().getConnection();
	}

	public void adiciona(Tarefa tarefa)
	{
		String sql = "Insert into tarefas (descricao, finalizado) values(?, ?)";
	
		try
		{
			PreparedStatement stmt =  connection.prepareStatement(sql);
		
			stmt.setString(1, tarefa.getDescricao());
			stmt.setBoolean(2, tarefa.isFinalizado());
		//	stmt.setDate(3, new Date(tarefa.getDataFinalizacao().getTimeInMillis()) );

			stmt.execute();
			stmt.close();
		}catch(SQLException e)
		{
			throw new RuntimeException(e);
		}
	}
	
	public List<Tarefa> lista()
	{
		try{
			List<Tarefa> tarefas = new ArrayList<Tarefa>();
			PreparedStatement stmt = this.connection.prepareStatement("select * from tarefas");
			ResultSet rs = stmt.executeQuery();
			
			while (rs.next())
			{
				Tarefa tarefa = new Tarefa();
				tarefa.setId(rs.getLong("id"));
				tarefa.setDescricao(rs.getString("descricao"));
				tarefa.setFinalizado(rs.getBoolean("finalizado"));
				Calendar data = Calendar.getInstance();
				data.setTime(rs.getDate("dataFinalizacao"));
				
				tarefas.add(tarefa);
			}
			rs.close();
			stmt.close();
			
			return tarefas;
		}
		catch (SQLException e)
		{
			throw new RuntimeException(e);
		}
	}

}

lista.jsp:

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
	<a href="novaTarefa">Criar nova tarefa</a>
	<br /><br />
	<table>
		<tr>
			<th>Id</th>
			<th>Descrição</th>
			<th>Finalizado?</th>
			<th>Data de finalização</th>
		</tr>
		<c:forEach items="${tarefas}" var="tarefa">
			<tr>
				<td>${tarefa.id}</td>
				<td>${tarefa.descricao}</td>
				<c:if test="${tarefa.finalizado eq false}">
					<td>Não finalizado</td>
				</c:if>
				<c:if "${tarefa.finalizado eq true}">
					<td>Finalizado</td>
				</c:if>	
				<td>
					<fmt:formatDate
						value="${tarefa.dataFinalizacao.time}"
						pattern="dd/MM/yyyy"/>
				</td>
			</tr>	
		</c:forEach>	
	</table>
</body>
</html>

web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>fj21-tarefas</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  
  <servlet>
  	<servlet-name>springmvc</servlet-name>
  	<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  	<init-param>
  		<param-name>contextConfigLocation</param-name>
  		<param-value>/WEB-INF/spring-context.xml</param-value>
  	</init-param>
  	<load-on-startup>1</load-on-startup>
  </servlet>
  
  <servlet-mapping>
  	<servlet-name>springmvc</servlet-name>
  	<url-pattern>/</url-pattern>
  </servlet-mapping>  
  
</web-app>

Desde já agradeço o auxílio de todos.

Atenciosamente,
Fernando Nascimento

#2

Problema associado aos Jar’s que estavam sendo utilizados. Versões não eram compatíveis.

Alterada conforme print em anexo.

Att.,
Fernando Nascimento

#3