谷粒商城项目（学习笔记十四）

第十一章：购物车服务

一、环境搭建

1）、新建gulimall-cart模组（略）

2）、导入前端页面（略）

3）、配置环境（略）

4）、前端页面跳转的调整（略）

二、分析购物车编写vo

编写Cart和CartItem的vo

@Data
public class Cart {

    List<CartItem> items;

    private Integer countNum;//商品数量

    private Integer countType;//商品类型数量

    private BigDecimal totalAmount;//商品总价

    private BigDecimal reduce = new BigDecimal("0.00");//减免价格

    public Integer getCountNum() {
        int count = 0;
        if (items != null && items.size() > 0) {
            for (CartItem item : items) {
                count += item.getCount();
            }
        }
        return count;
    }


    public Integer getCountType() {
        int count = 0;
        if (items != null && items.size() > 0) {
            for (CartItem item : items) {
                count += 1;
            }
        }
        return count;
    }


    public BigDecimal getTotalAmount() {
        BigDecimal amount = new BigDecimal("0");
        //1、计算购物项总价
        if (items != null && items.size() > 0) {
            for (CartItem item : items) {
                if(item.getCheck()){
                    BigDecimal totalPrice = item.getTotalPrice();
                    amount = amount.add(totalPrice);
                }
            }
        }

        //2、减去优惠总价
        BigDecimal subtract = amount.subtract(getReduce());

        return subtract;
    }
}

/**
 * 购物项内容
 */
@Data
public class CartItem {
    private Long skuId;
    private Boolean check = true;
    private String title;
    private String image;
    private List<String> skuAttr;
    private BigDecimal price;
    private Integer count;
    private BigDecimal totalPrice;

    /**
     * 计算当前项的总价
     * @return
     */
    public BigDecimal getTotalPrice() {

        return this.price.multiply(new BigDecimal("" + this.count));
    }

    public void setTotalPrice(BigDecimal totalPrice) {
        this.totalPrice = totalPrice;
    }
}

三、购物车身份鉴定

1）、添加redis和session

        <!--redis-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.session</groupId>
            <artifactId>spring-session-data-redis</artifactId>
        </dependency>

2）、编写session的配置和web的配置

@EnableRedisHttpSession
@Configuration
public class GulimallSessionConfig {

    @Bean
    public CookieSerializer cookieSerializer(){
        DefaultCookieSerializer cookieSerializer = new DefaultCookieSerializer();

        cookieSerializer.setDomainName("gulimall.com");
        cookieSerializer.setCookieName("GULISESSION");

        return cookieSerializer;
    }

    @Bean
    public RedisSerializer<Object> springSessionDefaultRedisSerializer() {
        return new GenericJackson2JsonRedisSerializer();
    }
}

@Configuration
public class GulimallWebConfig implements WebMvcConfigurer {


    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new CartInterceptor()).addPathPatterns("/**");
    }
}

3）、编写截断器

/**
 * 在执行目标方法之前，判断用户的登录状态。并封装传递(用户信息)给controller
 */
public class CartInterceptor implements HandlerInterceptor {

    public static ThreadLocal<UserInfoTo> threadLocal = new ThreadLocal<>();

    /**
     * 目标方法执行之前
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
                             Object handler) throws Exception {
        UserInfoTo userInfoTo = new UserInfoTo();

        HttpSession session = request.getSession();
        MemberRespVo member = (MemberRespVo) session.getAttribute(AuthServerConstant.LOGIN_USER);
        if(member != null){
            //用户登录
            userInfoTo.setUserId(member.getId());
        }

        Cookie[] cookies = request.getCookies();
        if(cookies!=null && cookies.length>0){
            for (Cookie cookie : cookies) {
                //user-key
                String name = cookie.getName();
                if(name.equals(CartConstant.TEMP_USER_COOKIE_NAME)){
                    userInfoTo.setUserKey(cookie.getValue());
                    userInfoTo.setTempUser(true);
                }
            }
        }

        //如果没有临时用户一定分配一个临时用户
        if(StringUtils.isEmpty(userInfoTo.getUserKey())){
            String uuid = UUID.randomUUID().toString();
            userInfoTo.setUserKey(uuid);
        }
        //目标方法执行之前
        threadLocal.set(userInfoTo);
        return true;
    }

    /**
     * 业务执行之后；分配临时用户，让浏览器保存
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

        UserInfoTo userInfoTo = threadLocal.get();

        //如果没有临时用户一定保存一个临时用户
        if(!userInfoTo.isTempUser()){
            //持续的延长临时用户的过期时间
            Cookie cookie = new Cookie(CartConstant.TEMP_USER_COOKIE_NAME, userInfoTo.getUserKey());
            cookie.setDomain("gulimall.com");
            cookie.setMaxAge(CartConstant.TEMP_USER_COOKIE_TIMEOUT);
            response.addCookie(cookie);
        }
    }
}

四、调通结构

1）、完善首页向购物车的跳转（前端）

2）、添加访问购物车方法

    @GetMapping("/cart.html")
    public String cartListPage() {
        //1、快速得到用户信息，id，user-key
        UserInfoTo userInfoTo = CartInterceptor.threadLocal.get();
        System.out.println(userInfoTo);
        return "cartList";
    }

3）、完善购物车向首页的跳转（前端）

五、购物车逻辑

//todo