用Java將Mysql行連續更新兩次導致錯誤

Question

每當我連續兩次更新（編輯）一行時，都會出現此錯誤：

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: -1
at java.util.Vector.elementData(Vector.java:730)
at java.util.Vector.elementAt(Vector.java:473)
at javax.swing.table.DefaultTableModel.getValueAt(DefaultTableModel.java:649)
at bicrijnmondcustomermanagement.DataView.EditActionPerformed(DataView.java:686)
at bicrijnmondcustomermanagement.DataView.access$400(DataView.java:18)
at bicrijnmondcustomermanagement.DataView$5.actionPerformed(DataView.java:366)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

這是有問題的代碼，我嘗試過在線查找，但沒有找到解決方案，所以我轉向StackOverflow：P謝謝大家。

private void EditActionPerformed(java.awt.event.ActionEvent evt) {                                     

   try{
       int row = Table_customer.getSelectedRow();
    String TClick = (Table_customer.getModel().getValueAt(row, 0).toString());
       String edit1 = lNaam.getText();
       String edit2 = lEmail.getText();
       String edit3 = lAdres.getText();
       String edit4 = lPlaats.getText();
       String edit5 = lPostcode.getText();
       String edit6 = lTelefoon.getText();
       String edit7 = lBedrijfsNaam.getText();

       String sql="update customers set naam='"+edit1+"',email='"+edit2+"',adres='"+edit3+"',plaats='"+edit4+"',postcode='"+edit5+"',telefoon='"+edit6+"',bedrijfsnaam='"+edit7+"'where KL_NR='"+TClick+"'";
       preparedStatement=connect.prepareStatement(sql);
       preparedStatement.execute();
    JOptionPane.showMessageDialog(null, "Updated");
   TheRefresher();


   }catch(SQLException | HeadlessException e){
   JOptionPane.showMessageDialog(null, e);
   }finally {
try{ //Update_tableCustomers();
resultSet.close(); preparedStatement.close(); }
catch(Exception e) { } }


}                     

附言 另外，如果我編輯另一行並返回到先前編輯的行，則效果很好，當我連續兩次編輯同一行時會出現問題。

Answer 1

看起來像這行：

 String TClick = (Table_customer.getModel().getValueAt(row, 0).toString());

因為堆棧跟蹤顯示以下內容：

at javax.swing.table.DefaultTableModel.getValueAt(DefaultTableModel.java:649)

所以getValueAt引發異常，可能是因為getSelectedRow返回-1。

檢查以確保getSelectedRow達到您的期望。

看到此內容： <JTable> .getSelectedRow（）返回-1

Answer 2

在執行此操作之前，您可能沒有選擇任何行。

private void EditActionPerformed(java.awt.event.ActionEvent evt)        
{                                     

  try{
   int row = Table_customer.getSelectedRow();
   System.out.println("selected row : " + row);
   if(row < 0) {
      JOptionPane.showMessageDialog(parentDialog, "Must select row" ); 
      return;
   }
    ...
 }