如何使用oop概念傳遞不同數據類型的ArrayList對象？

我試圖使用ArrayList將值傳遞給數據庫。後來我一個例外java.lang.ClassCastException: java.lang.String cannot be cast to model.OrderModel
這裏是我是如何讓用戶值可有人請檢查並幫助我做到這一點如何使用oop概念傳遞不同數據類型的ArrayList對象？

DefaultTableModel dtm = (DefaultTableModel) tblOrder.getModel(); 
    int numRow = dtm.getRowCount(); 
    int numCol = dtm.getColumnCount(); 
    try { 

    ArrayList<OrderModel> list = new ArrayList<OrderModel>();  
    for(int l = 0;l<numRow;l++){ 
     for(int j=0;j<numCol;j++){ 
      list.add((OrderModel) tblOrder.getValueAt(l, j));//this line may be the problem as i think 
     } 
    } 

    Order or = new Order(); 
    or.passingValuesToDB(list); 

     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
    }

，這是我在

public class Order { 
Connection con; 
    public void passingValuesToDB(ArrayList<OrderModel> list) { 
    try { 
     con = new DBconnector().connect(); 
     String sql = "INSERT INTO order (orderid, customername, item, qty, amount, total) VALUES (?,?,?,?,?,?)"; 

     PreparedStatement ps = con.prepareStatement(sql); 
     for(int i=0;i<list.size();i++){ 
      ps.setInt(1, list.get(i).getOrderid()); 
      ps.setString(2, list.get(i).getCustomername()); 
      ps.setString(3, list.get(i).getItem()); 
      ps.setDouble(4, list.get(i).getQty()); 
      ps.setDouble(5, list.get(i).getAmount()); 
      ps.addBatch(); 
     } 
     ps.executeQuery(); 
    } catch (SQLException ex) { 
     ex.printStackTrace(); 
    } 

    }

而我的方法已將所有獲得者設置爲OrderModel類別& Setteres。這裏的代碼

public class OrderModel { 
    private int orderid; 
    private String customername; 
    private String item; 
    private double qty; 
    private double amount; 
    private double total; 

     public OrderModel(int orderid,String customername,String item,Double qty,Double amount,Double total){ 
     this.orderid = orderid; 
     this.customername = customername; 
     this.item = item; 
     this.qty = qty; 
     this.amount=amount; 
     this.total=total; 
    } 

    public OrderModel() { 
     throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. 
    } 
    public int getOrderid() { 
     return orderid; 
    } 
    public void setOrderid(int orderid) { 
     this.orderid = orderid; 
    } 
    public String getCustomername() { 
     return customername; 
    } 
    public void setCustomername(String customername) { 
     this.customername = customername; 
    } 
    public String getItem() { 
     return item; 
    } 
    public void setItem(String item) { 
     this.item = item; 
    } 
    public double getQty() { 
     return qty; 
    } 
    public void setQty(double qty) { 
     this.qty = qty; 
    } 
    public double getAmount() { 
     return amount; 
    } 
    public void setAmount(double amount) { 
     this.amount = amount; 
    } 
    public double getTotal() { 
     return total; 
    } 
    public void setTotal(double total) { 
     this.total = total; 
    } 


}

來源

2015-09-14 LaĦiru M Pąrąnąvithąną

請告訴我有你的tblOrder，將您張貼類和堆棧跟蹤，以及是有幫助的。 –

是否確定tblOrder包含'OrderModel'實例？ –

tblOrder只包含（itemName，數量，價格，金額） –

(OrderModel) tblOrder.getValueAt(l, j)是問題

ValueAt(l, j)返回一個字符串（表列數據類型）。你可以不投String到OrderModel對象，他們是完全不同的對象。您應該使用行列值創建一個OrderModel對象。您可以使用setter或直接傳遞給構造函數。那麼你可以把它添加到您的ArrayList<OrderModel> list

ArrayList<OrderModel> list = new ArrayList<OrderModel>(); 

for (int l = 0; l < numRow; l++) { 

      int orderid = Integer.parseInt(tblOrder.getValueAt(l, 0).toString()); 
      String customername = tblOrder.getValueAt(l, 1).toString(); 
      String item = tblOrder.getValueAt(l, 2).toString(); 
      double qty = Double.parseDouble(tblOrder.getValueAt(l, 3).toString()); 
      double amount = Double.parseDouble(tblOrder.getValueAt(l, 4).toString()); 
      double total = Double.parseDouble(tblOrder.getValueAt(l, 5).toString()); 
      // OrderModel object 
      OrderModel ormod1 = new (orderid, customername, item, bla..bla..); 
      //then add OrderModel to the list 
      list.add(ormod1); 

}

來源

2015-09-14 07:17:07

Thanksx快速蝸牛:) –

如何使用oop概念傳遞不同數據類型的ArrayList對象？

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