简易购物车Servlet类实现

Java 发表评论
一 CartServlet实现
package servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import dao.ItemsDAO;
import entity.Cart;
import entity.Items;
public class CartServlet extends HttpServlet {
    private String action ; //表示购物车的动作 ,add,show,delete
    //商品业务逻辑类的对象
    private ItemsDAO idao = new ItemsDAO();
    
    
    /**
     * Constructor of the object.
     */
    public CartServlet() {
        super();
    }
    /**
     * Destruction of the servlet. <br>
     */
    public void destroy() {
        super.destroy(); // Just puts “destroy” string in log
        // Put your code here
    }
    /**
     * The doGet method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to get.
     *
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request,response);
    }
    /**
     * The doPost method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to post.
     *
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType(“text/html;charset=utf-8”);
        PrintWriter out = response.getWriter();
        if(request.getParameter(“action”)!=null)
        {
            this.action = request.getParameter(“action”);
            if(action.equals(“add”)) //如果是添加商品进购物车
            {
                if(addToCart(request,response))
                {
                    request.getRequestDispatcher(“/success.jsp”).forward(request, response);
                }
                else
                {
                    request.getRequestDispatcher(“/failure.jsp”).forward(request, response);
                }
            }
            if(action.equals(“show”))//如果是显示购物车
            {
                request.getRequestDispatcher(“/cart.jsp”).forward(request, response);
            }
            if(action.equals(“delete”)) //如果是执行删除购物车中的商品
            {
                if(deleteFromCart(request,response))
                {
                    request.getRequestDispatcher(“/cart.jsp”).forward(request, response);
                }
                else
                {
                    request.getRequestDispatcher(“/cart.jsp”).forward(request, response);
                }
            }
        }
        
    }
    //添加商品进购物车的方法
    private boolean addToCart(HttpServletRequest request, HttpServletResponse response)
    {
        String id = request.getParameter(“id”);
        String number = request.getParameter(“num”);
        Items item = idao.getItemsById(Integer.parseInt(id));
        
        //是否是第一次给购物车添加商品,需要给session中创建一个新的购物车对象
        if(request.getSession().getAttribute(“cart”)==null)
        {
            Cart cart = new Cart();
            request.getSession().setAttribute(“cart”,cart);
        }
        Cart cart = (Cart)request.getSession().getAttribute(“cart”);
        if(cart.addGoodsInCart(item, Integer.parseInt(number)))
        {
            return true;
        }
        else
        {
            return false;
        }
        
    }
    
    //从购物车中删除商品
    private boolean deleteFromCart(HttpServletRequest request, HttpServletResponse response)
    {
        String id = request.getParameter(“id”);
        Cart cart = (Cart)request.getSession().getAttribute(“cart”);
        Items item = idao.getItemsById(Integer.parseInt(id));
        if(cart.removeGoodsFromCart(item))
        {
            return true;
        }
        else
        {
            return false;
        }
    }
    
    /**
     * Initialization of the servlet. <br>
     *
     * @throws ServletException if an error occurs
     */
    public void init() throws ServletException {
        // Put your code here
    }

 

}

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