JAVAEE中用Session简单实现购物车功能示例代码

Session简单实现购物车功能

这个小程序主要就3个页面，一个商品列表页面(HomeServlet)，一个是提示加入购物车页面(AddCartTipServlet)，一个是显示购物车清单页面(ShowCartServlet)。

HomeServlet页面：

@WebServlet({ "/HomeServlet", "/home" })
public class HomeServlet extends HttpServlet {
  private static final long serialVersionUID = 1L;

  public HomeServlet() {
    super();
  }

  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    request.setCharacterEncoding("utf-8");
    response.setContentType("text/html;charset=utf-8");
    PrintWriter out = response.getWriter();
    out.print("
书单

");
    out.print("人类简史加入购物车
");
    out.print("未来简史加入购物车
");
    out.print("世界简史加入购物车
");
    out.print("时间简史加入购物车
");
    out.print("查看购物车
");
  }

  protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    doGet(request, response);
  }

}

AddCartTipServlet页面：

@WebServlet({ "/AddCartTipsServlet", "/addCartTip" })
public class AddCartTipsServlet extends HttpServlet {
  private static final long serialVersionUID = 1L;


  public AddCartTipsServlet() {
    super();
  }

  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    request.setCharacterEncoding("utf-8");
    response.setContentType("text/html;charset=utf-8");

    HttpSession session = request.getSession();
    List list = (List) session.getAttribute("cart");
    if(list==null){
      list=new ArrayList<>();
    }

    String id = request.getParameter("id");
    list.add(id);
    session.setAttribute("cart", list);

    System.out.println(list.toString());
    response.getWriter().println("已加入购物车
"
        + "继续购物
"
        + "查看购物车
");
  }

  protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    doGet(request, response);
  }

}

ShowCartSevlet页面

@WebServlet({ "/ShowCartServlet", "/show/cart" })
public class ShowCartServlet extends HttpServlet {
  private static final long serialVersionUID = 1L;

  public ShowCartServlet() {
    super();
  }


  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    request.setCharacterEncoding("utf-8");
    response.setContentType("text/html;charset=utf-8");
    PrintWriter out = response.getWriter();
    List list = (List)request.getSession().getAttribute("cart");
    if(list!=null){   
      out.print("你的购物清单：
");
      for (String string : list) {
        out.println(DBUtils.findById(string)+"
");
      }
      out.println("
继续购物
");
    }else{
      out.println("你还没有将商品添加到购物车
"
          + "返回商品列表
");
    }
  }

  protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    doGet(request, response);
  }

}

DBUtils：存储着商品信息

public class DBUtils {
  private static Map map = new HashMap<>();

  static{
    map.put("1", "人类简史");
    map.put("2", "未来简史");
    map.put("3", "世界简史");
    map.put("4", "时间简史");
  }

  public static String findById(String id){
    return map.get(id);
  }

}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。