Aula 10 exercício 6 (Disponibilizando o carrinho para as Views)

Boa tarde.

Estou errando em algum lugar mas não consegui identificar. Quando tento acessar a página do carrinho dá o erro "HTTP Status 500 - javax.el.PropertyNotFoundException: Property 'quantidade' not found on type br.com.casadocodigo.loja.models.CarrinhoCompras"

Minha classe CarrinhoCompras está assim:

package br.com.casadocodigo.loja.models;

import java.util.LinkedHashMap;
import java.util.Map;

import org.springframework.stereotype.Component;

@Component
public class CarrinhoCompras {

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

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

    private int getQuantidade(CarrinhoItem item) {
        if (!itens.containsKey(item)) {
            itens.put(item, 0);
        }

        return itens.get(item);
    }

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

}

package br.com.casadocodigo.loja.conf;

import org.springframework.context.MessageSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.support.ReloadableResourceBundleMessageSource;
import org.springframework.format.datetime.DateFormatter;
import org.springframework.format.datetime.DateFormatterRegistrar;
import org.springframework.format.support.DefaultFormattingConversionService;
import org.springframework.format.support.FormattingConversionService;
import org.springframework.web.multipart.MultipartResolver;
import org.springframework.web.multipart.support.StandardServletMultipartResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

import br.com.casadocodigo.loja.controllers.HomeController;
import br.com.casadocodigo.loja.daos.ProdutoDAO;
import br.com.casadocodigo.loja.infra.FileSaver;
import br.com.casadocodigo.loja.models.CarrinhoCompras;

@EnableWebMvc
@ComponentScan(basePackageClasses = { HomeController.class, ProdutoDAO.class,
        FileSaver.class, CarrinhoCompras.class})
public class AppWebConfiguration {

    @Bean
    public InternalResourceViewResolver internalResourceViewResolver() {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".jsp");

        resolver.setExposedContextBeanNames("carrinhoCompras");

        return resolver;
    }

    @Bean
    public MessageSource messageSource() {
        ReloadableResourceBundleMessageSource messageSource = 
                new ReloadableResourceBundleMessageSource();

        messageSource.setBasename("/WEB-INF/messages");
        messageSource.setDefaultEncoding("UTF-8");
        messageSource.setCacheSeconds(1);

        return messageSource;
    }
    //Esse método abaixo é para não ter que ficar definindo o pattern nos atributos DateTimeFormat
    @Bean
    public FormattingConversionService mvcConversionService() {
        DefaultFormattingConversionService conversionService = 
                new DefaultFormattingConversionService();
        DateFormatterRegistrar registrar = new DateFormatterRegistrar();
        registrar.setFormatter(new DateFormatter("dd/MM/yyyy"));
        registrar.registerFormatters(conversionService);

        return conversionService;
    }

    @Bean
    public MultipartResolver multipartResolver() {
        return new StandardServletMultipartResolver();
    }
}