我不能插入數據到我的數據庫後刪除我的文本字段的內容

Question

class MyDocumentListener implements DocumentListener { 

    public void insertUpdate(DocumentEvent e) { 

     if(typeComboBox3.getSelectedIndex()==0) { 
         JOptionPane.showMessageDialog(null, "Please select an item type"); 
         serialnumberTextField3.setText(""); 
        } 

        else { 
        String sql2 = "INSERT INTO product(type, materialcode, serialnumber, status, careof, date, name, accountnumber, contactnumber) VALUES(?, ?, ?, ?, ?, ?, ?, ?, ?)"; 
        try { 

        pst1 = conn.prepareStatement(sql2); 
        pst1.setString(1, (String)typeComboBox3.getSelectedItem()); 
        pst1.setString(2, (String)materialcodeComboBox3.getSelectedItem()); 
        pst1.setString(3, serialnumberTextField3.getText()); 
        pst1.setString(4, (String)statusComboBox3.getSelectedItem()); 
        pst1.setString(5, (String)careofComboBox3.getSelectedItem()); 
        pst1.setString(6, "2012-03-08"); 
        pst1.setString(7, ""); 
        pst1.setString(8, ""); 
        pst1.setString(9, ""); 
        pst1.execute(); 

        JOptionPane.showMessageDialog(null, "Type: "+typeComboBox3.getSelectedItem()+"\n"+"Material Code: "+materialcodeComboBox3.getSelectedItem()+"\n"+"Serial Number: "+serialnumberTextField3.getText()+"\n"+"Care of: "+careofComboBox3.getSelectedItem()+"\n\n"+"Product Successfully Added"); 

        serialnumberTextField3.setText(""); 
        //serialnumberTextField3.requestFocus(); 

        } 

        catch(Exception ex) { 
         System.out.println(ex); 
        } 

        UpdateTable(); 

        } 

    } 

    public void removeUpdate(DocumentEvent e) { 



    } 

    public void changedUpdate(DocumentEvent e) { 



    } 

} 

當一些粘貼在文本字段，按OK在確認數據有消息對話框後，我的程序自動插入數據到數據庫已成功插入我嘗試使用serialnumberTextField3.setText（「」）來清除TextField，因爲某些原因，TextField奇怪地不清除。

Answer 1

試試這個：

if(typeComboBox3.getSelectedIndex()==0) { 
new Thread(){ 
    @Override 
    public void run(){ 
     JOptionPane.showMessageDialog(null, "Please select an item type"); 
     serialnumberTextField3.setText(""); 
    } 
}.start(); 

}