Question

现在我有一个JTable，只要按下一个按钮，它就会显示我创建的MySql数据库中的项目名称和项目价格。我遇到的问题是保持桌面上物品价格的运行总额。

enter code here  private void waterbuttonActionPerformed(java.awt.event.ActionEvent evt) {                                            
    // TODO add your handling code here:
    try{
     st = connection.createStatement();   
    String query;
    query = "SELECT itemName, itemPrice FROM item WHERE itemID = '11111'";
    String itemName = " ",itemPrice =" ";  

      ResultSet rs = st.executeQuery(query);

       if(rs != null){
        while(rs.next())
        { 
         itemName = rs.getString(1);
         itemPrice = rs.getString(2);
        }
      model.addRow(new Object[]{itemName, itemPrice});

       }
       String holder = model.getValueAt(WIDTH, 1).toString(); 
       total += Double.parseDouble(holder);
       System.out.println(total);
         } catch (SQLException | NumberFormatException | ArrayIndexOutOfBoundsException ex) {}

变量“total”是全局double，变量“model”是DefualtTableModel。我是否在正确的轨道上获得这个总计或者我应该尝试一种完全不同的方法？请帮助我在智慧结束。

Answer 1

使用循环计算total

   int row;
   for(row= 0; row<=model.getRowCount(); row++){
   String holder = model.getValueAt(row, 1).toString(); // I do not know why you are writing WIDTH here. 

   total += Double.parseDouble(holder);
   System.out.println(total);
   }

计算JTable中的值

1 个答案: