Dúvida no Ex. 2 da Aula 12 - Carrinho de compras

olá pessoal, estou recebendo esse erro

type Exception report

message An exception occurred processing JSP page /WEB-INF/views/carrinho/itens.jsp at line 110

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

exception

org.apache.jasper.JasperException: An exception occurred processing JSP page /WEB-INF/views/carrinho/itens.jsp at line 110

107:                       <tr>
108:                       
109:                       <td class="cart-img-col"><img src="http://cdn.shopify.com/s/files/1/0155/7645/products/css-eficiente-featured_large.png?v=1435245145" width="71px" height="100px"/></td><td class="item-title">T�TULO DO LIVRO AQUI</td>
110:                       <td class="item-title"> ${item.Produto.titulo }</td>
111:                       <td class="numeric-cell">${item.tipoPreco }</td>
112:                       <td class="quantity-input-cell"><input type="number" min="0" readonly="readonly" id="quantidade" name="quantidade" 
113:                               value="${carrinhoCompras.getQuantidade(item)}" /></td>


Stacktrace:
    org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:568)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:470)
    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:728)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
    org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:172)
    org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
    org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1228)
    org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1011)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:955)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
root cause

javax.el.PropertyNotFoundException: Property 'Produto' not found on type java.lang.String
    javax.el.BeanELResolver$BeanProperties.get(BeanELResolver.java:229)
    javax.el.BeanELResolver$BeanProperties.access$400(BeanELResolver.java:206)
    javax.el.BeanELResolver.property(BeanELResolver.java:317)
    javax.el.BeanELResolver.getValue(BeanELResolver.java:85)
    org.apache.jasper.el.JasperELResolver.getValue(JasperELResolver.java:104)
    org.apache.el.parser.AstValue.getValue(AstValue.java:183)
    org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:185)
    org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:1026)
    org.apache.jsp.WEB_002dINF.views.carrinho.itens_jsp._jspx_meth_c_005fforEach_005f0(itens_jsp.java:375)
    org.apache.jsp.WEB_002dINF.views.carrinho.itens_jsp._jspService(itens_jsp.java:207)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
    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:728)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
    org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:172)
    org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
    org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1228)
    org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1011)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:955)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)

package org.SpringMvc.loja.modelos;

import java.io.Serializable;
import java.math.BigDecimal;
import java.util.Collection;
import java.util.LinkedHashMap;
import java.util.Map;

import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
import org.springframework.web.context.WebApplicationContext;

import com.sun.org.apache.xml.internal.security.utils.ElementCheckerImpl.InternedNsChecker;
import com.sun.xml.internal.ws.developer.Serialization;


@Component
@Scope(value=WebApplicationContext.SCOPE_SESSION)
public class CarrinhoCompras implements Serializable {

    private static final long serialVersionUID = 1L;

    private Map<CarrinhoItem, Integer> itens = new LinkedHashMap<>();

    public void add(CarrinhoItem item) {
        itens.put(item, getQuantidade(item) + 1);

    }

    public Integer getQuantidade(CarrinhoItem item) {
        if (!itens.containsKey(item)) {
            itens.put(item, 0);
        }
        return itens.get(item);
    }

    public int getQuantidade() {
        return itens.values().stream().reduce(0, (proximo, acumulador) -> proximo + acumulador);
    }


    public BigDecimal getTotal(CarrinhoItem item){
        return item.getTotal(getQuantidade(item));

    }

    public BigDecimal getTotal(){
        BigDecimal total = BigDecimal.ZERO;

        for(CarrinhoItem item : itens.keySet()){
            total = total.add(getTotal(item));
        }
        return total;
    }

    public Collection<CarrinhoItem> getItens() {
        return this.itens.keySet();
    }


}

package org.SpringMvc.loja.modelos;

import java.io.Serializable;
import java.math.BigDecimal;

public class CarrinhoItem implements Serializable {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    private Produto produto;
    private TipoPreco tipoPreco;

    public Produto getProduto() {
        return this.produto;
    }


    public void setProduto(Produto produto) {
        this.produto = produto;
    }


    public TipoPreco getTipoPreco() {
        return tipoPreco;
    }


    public void setTipoPreco(TipoPreco tipoPreco) {
        this.tipoPreco = tipoPreco;
    }


    public CarrinhoItem(Produto produto, TipoPreco tipoPreco) {
        this.produto = produto;
        this.tipoPreco = tipoPreco;

    }


    public BigDecimal getPreco(){
        return produto.precoPara(tipoPreco);

    }


    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((produto == null) ? 0 : produto.hashCode());
        result = prime * result + ((tipoPreco == null) ? 0 : tipoPreco.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        CarrinhoItem other = (CarrinhoItem) obj;
        if (produto == null) {
            if (other.produto != null)
                return false;
        } else if (!produto.equals(other.produto))
            return false;
        if (tipoPreco != other.tipoPreco)
            return false;
        return true;
    }


    public BigDecimal getTotal(int quantidade) {
        return this.getPreco().multiply(new BigDecimal(quantidade));
    }



}

itens.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://www.springframework.org/tags" prefix="s" %>
<!DOCTYPE html>
<html>
<head>
    <c:url value="/" var="contextPath" />
      <meta charset="utf-8"/>
          <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/>
          <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1"/>
        <link rel="icon"
            href="//cdn.shopify.com/s/files/1/0155/7645/t/177/assets/favicon.ico?11981592617154272979"
            type="image/ico" />
        <link href="https://plus.googlecom/108540024862647200608"
            rel="publisher"/>
        <title>Livros de Java, SOA, Android, iPhone, Ruby on Rails e
            muito mais - Casa do Código</title>
        <link href="${contextPath}resources/css/cssbase-min.css"
            rel="stylesheet" type="text/css" media="all" />
        <link href='http://fonts.googleapis.com/css?family=Droid+Sans:400,700'
            rel='stylesheet'/>
        <link href="${contextPath}resources/css/fonts.css"
            rel="stylesheet" type="text/css" media="all" />
        <link href="${contextPath}resources/css/fontello-ie7.css"
            rel="stylesheet" type="text/css" media="all" />
        <link href="${contextPath}resources/css/fontello-embedded.css"
            rel="stylesheet" type="text/css" media="all" />
        <link href="${contextPath}resources/css/fontello.css"
            rel="stylesheet" type="text/css" media="all" />
        <link href="${contextPath}resources/css/style.css"
            rel="stylesheet" type="text/css" media="all" />
        <link href="${contextPath}resources/css/layout-colors.css"
            rel="stylesheet" type="text/css" media="all" />
        <link href="${contextPath}resources/css/responsive-style.css"
            rel="stylesheet" type="text/css" media="all" />
        <link href="${contextPath}resources/css/guia-do-programador-style.css" 
            rel="stylesheet" type="text/css"  media="all"  />
        <link href="${contextPath}resources/css/produtos.css" 
            rel="stylesheet" type="text/css"  media="all"  />
        <link rel="canonical" href="http://www.casadocodigo.com.br/" />    
</head>
<body>

  <header id="layout-header">
        <div class="clearfix container">
            <a href="/" id="logo">
            </a>
            <div id="header-content">
                <nav id="main-nav">

                    <ul class="clearfix">
                        <li><a href="${s:mvcUrl('CCC#itens').build() }" rel="nofollow">Carrinho (${carrincoCompras.quantidade})</a></li>

                        <li><a href="/pages/sobre-a-casa-do-codigo" rel="nofollow">Sobre Nós</a></li>

                        <li><a href="/pages/perguntas-frequentes" rel="nofollow">Perguntas Frequentes</a></li>
                    </ul>
                </nav>
            </div>
        </div>
    </header>

    <nav class="categories-nav">
        <ul class="container">
            <li class="category"><a href="http://www.casadocodigo.com.br">Home</a></li>
            <li class="category"><a href="/collections/livros-de-agile">
                    Agile </a></li>
            <li class="category"><a href="/collections/livros-de-front-end">
                    Front End </a></li>
            <li class="category"><a href="/collections/livros-de-games">
                    Games </a></li>
            <li class="category"><a href="/collections/livros-de-java">
                    Java </a></li>
            <li class="category"><a href="/collections/livros-de-mobile">
                    Mobile </a></li>
            <li class="category"><a
                href="/collections/livros-desenvolvimento-web"> Web </a></li>
            <li class="category"><a href="/collections/outros"> Outros </a></li>
        </ul>
    </nav>

    <section class="container middle">
          <h2 id="cart-title">Seu carrinho de compras</h2>


            <table id="cart-table">
              <colgroup>
                <col class="item-col"/>
                <col class="item-price-col"/>
                <col class="item-quantity-col"/>
                <col class="line-price-col"/>
                <col class="delete-col"/>
              </colgroup>
              <thead>
                <tr>
                  <th class="cart-img-col"></th>
                  <th width="65%">Item</th>
                  <th width="10%">Preço</th>
                  <th width="10%">Quantidade</th>
                  <th width="10%">Total</th>
                  <th width="5%"></th>
                </tr>
              </thead>
              <tbody>
                  <c:forEach   items="${carrinhoCompras.itens} " var="item">
                      <tr>

                      <td class="cart-img-col"><img src="http://cdn.shopify.com/s/files/1/0155/7645/products/css-eficiente-featured_large.png?v=1435245145" width="71px" height="100px"/></td><td class="item-title">TÍTULO DO LIVRO AQUI</td>
                      <td class="item-title"> ${item.produto.titulo }</td>
                      <td class="numeric-cell">${item.tipoPreco }</td>
                      <td class="quantity-input-cell"><input type="number" min="0" readonly="readonly" id="quantidade" name="quantidade" 
                              value="${carrinhoCompras.getQuantidade(item)}" /></td>
                      <td class="numeric-cell">${carrinhoCompras.getTotal(item)}</td>
                      <td class="remove-item">
                      <form action="" method="POST">
                          <input type="image"
                        src="http:////cdn.shopify.com/s/files/1/0155/7645/t/177/assets/excluir.png?157580795780530083" 
                      alt="Excluir" title="Excluir"/></td>    
                      </form>

                  </tr>
                  </c:forEach>
              </tbody>

                  <tfoot>
                    <tr>
                      <td colspan="3"><input type="submit" class="checkout" name="checkout" value="Finalizar compra" /></td>
                      <td class="numeric-cell">${carrinhoCompras.total}</td>
                      <td class="quantity-input-cell"><input type="submit" class="update-cart" disabled="disabled" name="update" value=""/></td>

                    </tr>
                  </tfoot>
            </table>

          <h2>Você já conhece os outros livros da Casa do Código?</h2>
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          </ul>

          <h2><a href="http://www.casadocodigo.com.br">Veja todos os livros que publicamos!</a></h2>
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package org.SpringMvc.loja.controller;

import org.SpringMvc.loja.daos.ProdutoDAO;
import org.SpringMvc.loja.modelos.CarrinhoCompras;
import org.SpringMvc.loja.modelos.CarrinhoItem;
import org.SpringMvc.loja.modelos.Produto;
import org.SpringMvc.loja.modelos.TipoPreco;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.servlet.ModelAndView;

@Controller
@Scope(value=WebApplicationContext.SCOPE_REQUEST)
@RequestMapping("/carrinho")
public class CarrinhoComprasController{

    @Autowired
    private ProdutoDAO produtoDAO;

    @Autowired
    private CarrinhoCompras carrinho;

    @RequestMapping("/add") 
    public ModelAndView add(Integer produtoId, TipoPreco tipoPreco){
        ModelAndView modelAndView = new ModelAndView("redirect:/carrinho");
        CarrinhoItem carrinhoItem = criaItem(produtoId,tipoPreco);
        carrinho.add(carrinhoItem);

        return modelAndView;
    }

    @RequestMapping(method=RequestMethod.GET)
    public ModelAndView itens(){
        System.out.println("acessando carrinho/itens");
        return new ModelAndView("/carrinho/itens");
    }

    private CarrinhoItem criaItem(Integer produtoId, TipoPreco tipoPreco) {
        Produto produto=produtoDAO.find(produtoId);
        CarrinhoItem carrinhoItem = new CarrinhoItem(produto, tipoPreco);

        return carrinhoItem;
    }

}