【范例】赵雅智_购物车（4）删除购物车的购物项 _Web前端

【实例】赵雅智_购物车（4）删除购物车的购物项

删除购物项

Listcart.jsp

新建DemeteByIdServlet.java

package www.hbsi.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 www.hbsi.domain.Cart;
import www.hbsi.service.BookService;
import www.hbsi.service.BookServiceImpl;

public class DeleteByIdServlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		//获取ID
		String id = request.getParameter("id");
		//删除购物车里的购物项，获取车
		Cart cart = (Cart) request.getSession().getAttribute("cart");
		//调用方法，从购物项里删除书
		BookService service = new BookServiceImpl();
		service.deleteById(id,cart);
		 
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}

1. 创建删除服务项BookService：

package www.hbsi.service;

import java.util.List;

import www.hbsi.domain.Book;
import www.hbsi.domain.Cart;

public interface BookService {
	//查询所有书籍
	public List<Book> getAll();
	
	//根据ID查找书籍
	public Book findById(String id);

	//删除购物项
	public void deleteById(String id, Cart cart);
}

2. 实现删除服务项BookServiceImpl：

package www.hbsi.service;

import java.util.List;

import www.hbsi.dao.BookDao;
import www.hbsi.dao.BookDaoImpl;
import www.hbsi.domain.Book;
import www.hbsi.domain.Cart;

public class BookServiceImpl implements BookService {

	BookDao bd = new BookDaoImpl();
	public Book findById(String id) {
		// TODO Auto-generated method stub
		return bd.findById(id);
	}

	public List<Book> getAll() {
		// TODO Auto-generated method stub
		return bd.getAll();
	}

	public void deleteById(String id, Cart cart) {
		// TODO Auto-generated method stub
		cart.getMap().remove(id);
		
		
	}

}

DelectByIdServlet.java

package www.hbsi.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 www.hbsi.domain.Cart;
import www.hbsi.service.BookService;
import www.hbsi.service.BookServiceImpl;

public class DeleteByIdServlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		//获取ID
		String id = request.getParameter("id");
		//删除购物车里的购物项，获取车
		Cart cart = (Cart) request.getSession().getAttribute("cart");
		//调用方法，从购物项里删除书
		BookService service = new BookServiceImpl();
		service.deleteById(id,cart);
		//转回购买界面
		request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response);

		 
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}

删除的时候加一个提示

listcard.Jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>   
    <title>购物车显示页面</title> 
        <script type="text/javascript">
      function deletitem(id){
           var  b = window.confirm("确定要删除吗？");
           if(b){
				window.location.href="${pageContext.request.contextPath}/deletedById.do?id="+id;           
           }
       
       }
    </script>	   
  </head>
  
  <body style="text-align:center">
     <h2>您购买了如下商品</h2>

      <table border="1" width="80%">
        <tr>
           <td>编号</td>
           <td>书名</td>
           <td>单价</td>
           <td>数量</td>
           <td>小计</td>
           <td>操作</td>   
        </tr>
        <c:forEach var="me" items="${cart.map}">
          <tr>
          <td>${me.key}</td>
           <td>${me.value.book.name}</td>
           <td>${me.value.book.price}</td>
           <td>${me.value.quantity}</td>
           <td>${me.value.price}</td>
            <td>
            <!-- 删一个购物项不是购物车 -->
              <a href="javascript:deletitem(${me.key})">删除</a>
              <!--  <a href="${pageContext.request.contextPath}/deletedById.do?id=${me.key}">删除</a>-->
           
           
           </td>     
          
          </tr>
          
        
        </c:forEach>
         <tr>
           <td colspan="3">总价</td>
           <td colspan="2">${cart.price}</td>
        </tr>
      
      </table>
      </body>
</html>