無法將java.lang.Object轉換爲int

Question

我從JTable下載數字時遇到問題。在Eclipse中，我擁有JavaSE 1.7並且它都可以。我在IntelliJ IDEA中打開了我的項目並選擇了SDK java jdk 1.8。

private int; 
public void tableEdit(final JTable table) { 

     table.getModel().addTableModelListener(new TableModelListener() { 
      @Override 
      public void tableChanged(TableModelEvent e) { 
       // TODO Auto-generated method stub 
       if (table.getCellEditor() != null) { 

        int col = table.getSelectedColumn(); 
        id = (int)table.getValueAt(table.getSelectedRow(), 0); //ERROR 

錯誤：

java: incompatible types: java.lang.Object cannot be converted to int 

編輯：

新的問題： JTable中我有2場，ID並從下拉框選擇值後場2（組合框）想要檢索來自ID字段的值，以便他們知道我需要更新哪一行。

categoryBox.addItemListener(new ItemListener() { 
      public void itemStateChanged(ItemEvent event) { 
       if (newrow_flag == 0) { 
        JComboBox comboBox = (JComboBox) event.getSource(); 
        Object item = event.getItem(); 
        if (event.getStateChange() == ItemEvent.SELECTED 
          && box_flag_category > 0) { 

         Category selected_category = (Category) categoryBox 
           .getSelectedItem(); 

         int rowid = Integer.getInteger(itemTable.getValueAt(
           itemTable.getSelectedRow(), 0).toString()); //Error 

         id_category = selected_category.getId(); 


         fireItemEvent(new ItemsEvent(rowid, "produkty", null, 
           null, null, id_category, id_company, "update"), 
           "box_category"); 

        } 
        box_flag_category++; 
       } 
      } 
     }); 

和錯誤：

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException 
    at com.magazyn.view.View$9.itemStateChanged(View.java:659) 
    at javax.swing.JComboBox.fireItemStateChanged(JComboBox.java:1223) 
    at javax.swing.JComboBox.selectedItemChanged(JComboBox.java:1280) 
    at javax.swing.JComboBox.contentsChanged(JComboBox.java:1327) 
    at javax.swing.AbstractListModel.fireContentsChanged(AbstractListModel.java:118) 
    at javax.swing.DefaultComboBoxModel.setSelectedItem(DefaultComboBoxModel.java:93) 
    at javax.swing.JComboBox.setSelectedItem(JComboBox.java:576) 
    at javax.swing.JComboBox.setSelectedIndex(JComboBox.java:622) 
    at javax.swing.plaf.basic.BasicComboPopup$Handler.mouseReleased(BasicComboPopup.java:834) 
    at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:290) 
    at java.awt.Component.processMouseEvent(Component.java:6527) 
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3321) 
    [...] 

錯誤指向該行：

int rowid = Integer.getInteger(itemTable.getValueAt(
           itemTable.getSelectedRow(), 0).toString()); 

Answer 1

遠遠看錯誤：

java: incompatible types: java.lang.Object cannot be converted to int

再看看行拋出錯誤：

id = (int)table.getValueAt(table.getSelectedRow(), 0); 

現在，您可以看到，您正試圖將Object投射到int。這是不允許的。所以，你需要多一點創意：

int id = Integer.parseInt(table.getValueAt(table.getSelectedRow(), 0).toString()); 

Answer 2

見類JTable中

public Object getValueAt(int row, int column) { 
     return getModel().getValueAt(convertRowIndexToModel(row), 
            convertColumnIndexToModel(column)); 
    } 

方法返回類型爲對象。

使用Integer.parseInt();

Answer 3

I have a problem with downloading the number from JTable.

• 放整數值直接JTable/XxxTableModel，以避免任何的解析在運行時

• 的JTable在其XxxTableModel指定to store various data types

• （爲DefaultTableModel ISN不需要）然後覆蓋getColumnClass

---

編輯

重：

@christopher, when I chose value from ComboBox i get error Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.String at com.magazyn.view.View$9.itemStateChanged(View.java:659) at javax.swing.JComboBox.fireItemStateChanged(JComboBox.java:1223) at javax.swing.JComboBox.selectedItemChanged(JComboBox.java:1280)

• 不要把JComboBox中到JTable中，閱讀甲骨文教程How to use Tables - Using a Combo Box as an Editor的工作代碼示例（String實例），模型應僅存儲JComboBox中的初始或最後選定值作爲編輯器

個

• 放號碼的JComboBox/DefaultComboBoxModel直接，然後返回編號爲

• TableModelListener發射CellEditor的（）== NULL後一個事件，然後代碼並不讓我SENCE