Android网络编程之一个Android下菜单系统模块的实现(服务器端—结算功能(中部))

这次我们向主订单信息下面添加订单明细信息，也是遵循DAO模式，然后将数据拼成html传回客户端

com.moka.entity中新建一个实体类QueryOrderDetail:

/**
 *    用于封装查一个对应订单的明细信息的实体类
 */
public class QueryOrderDetail {
    // 菜名
    private String dishName;
    // 菜价
    private int price;
    // 数量
    private int dishNum;
    // 总价
    private int totalPrice;
    // 备注
    private String remark;
    
getters & setters ..
    
}
View Code

在上次写好的PayDao与PayDaoImpl中添加一个新方法getOrderDetailById():

public interface PayDao {
    // 取得主订单信息
    public QueryOrder getOrderById(int id);
    
    // 取得详细订单信息
    public List<QueryOrderDetail> getOrderDetailById(int id);
}
@Override
    public List getOrderDetailById(int id) {
        // jdbc连接数据库准备工作
        DBUtil util = new DBUtil(); 
        Connection conn = util.openConnection();
        
        // 插入数据库操作用，使用union合并最后单算出来的总价
        String queryOrderDetailSql = "select mt.name, mt.price, odt.num, mt.price * odt.num totalPrice, odt.remark from orderdetailtbl odt " +
                              "join menutbl mt on odt.menuId = mt.id where odt.orderId = ? " +
                              "union  select '', '', '', sum(mt.price * odt.num) allPrice, '' from orderdetailtbl odt " +
                              "join menutbl mt on odt.menuId = mt.id where odt.orderId = ? "    ;
        PreparedStatement ps = null;
        ResultSet resultSet = null;
        
        // 准备传回的QueryOrderDetail列表
        List<QueryOrderDetail> list = new ArrayList<QueryOrderDetail>();
        try {
            ps = conn.prepareStatement(queryOrderDetailSql);
            ps.setInt(1, id);
            ps.setInt(2, id);
            resultSet = ps.executeQuery();
            while (resultSet.next()) {
                // 实例化封装数据的QueryOrderDetail类
                QueryOrderDetail queryOrderDetail = new QueryOrderDetail();
                // 使用所获数据填充QueryOrderDetail
                queryOrderDetail.setDishName(resultSet.getString(1));
                queryOrderDetail.setPrice(resultSet.getInt(2));
                queryOrderDetail.setDishNum(resultSet.getInt(3));
                queryOrderDetail.setTotalPrice(resultSet.getInt(4));
                queryOrderDetail.setRemark(resultSet.getString(5));
                // 装入List
                list.add(queryOrderDetail);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (resultSet != null) {
                    resultSet.close();
                    resultSet = null;
                }
                if (ps != null) {
                    ps.close();
                    ps = null;
                }
                if (conn != null) {
                    conn.close();
                    conn = null;
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return list;
    }
View Code

然后在上次写好的QueryOrderServlet中添加对应代码，拼成html：

public class QueryOrderServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        resp.setContentType("text/html");
        PrintWriter ps = new PrintWriter(resp.getOutputStream());
        
        // 取得传来的orderId
        String id = req.getParameter("id");
        int orderId = Integer.parseInt(id);
        
        // 获取PayDao实例
        PayDao payDao = new PayDaoImpl();
        
        // 得到主订单数据实例
        QueryOrder order = payDao.getOrderById(orderId);
        
        // 得到订单明细数据实例列表
        List<QueryOrderDetail> list = payDao.getOrderDetailById(orderId);
        
        // 从主订单数据实例中取出数据
        String waiterName = order.getName();
        String orderTime = order.getOrderTime();
        int personNum = order.getPersonNum();
        int tableId = order.getTableId();
        
        // 将数据写进Html页面传回客户端
        ps.println("<HTML>");
        // 注：下面一句中head标签内要添加一条元数据，声明字符集为utf-8, 否则传回中文会显示乱码
        ps.println("  <HEAD><meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\"></HEAD>");
        ps.println("  <BODY>");
        ps.print("<table>");
            ps.print("<tr>");
            
                ps.print("<th>");
                    ps.print("Order ID");
                ps.print("</th>");
                
                ps.print("<th>");
                    ps.print("Waiter Name");
                ps.print("</th>");
                
                ps.print("<th>");
                    ps.print("Order Time");
                ps.print("</th>");
                
                ps.print("<th>");
                    ps.print("Person Num");
                ps.print("</th>");
                
                ps.print("<th>");
                    ps.print("Table ID");
                ps.print("</th>");
                
            ps.print("</tr>");
            
            ps.print("<tr>");
                
                ps.print("<td>");
                    ps.print(id);
                ps.print("</td>");
                
                ps.print("<td>");
                    ps.print(waiterName);
                ps.print("</td>");
                
                ps.print("<td>");
                    ps.print(orderTime);
                ps.print("</td>");
                
                ps.print("<td>");
                    ps.print(personNum);
                ps.print("</td>");
                
                ps.print("<td>");
                    ps.print(tableId);
                ps.print("</td>");
                
            ps.print("</tr>");
            
            ps.print("<tr>");
            
            ps.print("<th>");
                ps.print("Dish Name");
            ps.print("</th>");
            
            ps.print("<th>");
                ps.print("Price");
            ps.print("</th>");
            
            ps.print("<th>");
                ps.print("Dishes Num");
            ps.print("</th>");
            
            ps.print("<th>");
                ps.print("Total Price");
            ps.print("</th>");
            
            ps.print("<th>");
                ps.print("Remark");
            ps.print("</th>");
            
        ps.print("</tr>");
        
        // 循环取出所有明细数据,拼成html
        Iterator<QueryOrderDetail> iterator = list.iterator();
        while (iterator.hasNext()) {
            QueryOrderDetail detail = iterator.next();
            String dishName = detail.getDishName();
            int price = detail.getPrice();
            int dishNum = detail.getDishNum();
            int totalPrice = detail.getTotalPrice();
            String remark = detail.getRemark();
            
            ps.print("<tr>");
            
                ps.print("<td>");
                    ps.print(dishName);
                ps.print("</td>");
                
                ps.print("<td>");
                    ps.print(price);
                ps.print("</td>");
                
                ps.print("<td>");
                    ps.print(dishNum);
                ps.print("</td>");
                
                ps.print("<td>");
                    ps.print(totalPrice);
                ps.print("</td>");
                
                ps.print("<td>");
                    ps.print(remark);
                ps.print("</td>");
            
            ps.print("</tr>");
        }
        
        ps.print("</table>");
        ps.println("  </BODY>");
        ps.println("</HTML>");
        ps.flush();
        ps.close();
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        doGet(req, resp);
    }

}
View Code

拿第20张订单试验，实现后，返回客户端的效果如图：

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原文地址：https://www.cnblogs.com/moka/p/3083403.html