java - 如何在更新后自动刷新 jComboBox 数据？

Question

我有一个 jComboBox 从 MySQL 服务器数据库获取数据。

当我向数据库添加新数据时，jComboBox 不显示它，我必须重新打开我的程序以将新数据添加到 jComboBox。

如何自动刷新jComboBox数据？

这是我的代码:

private void dataComboBox(){
    try {
        Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/shop","root","");
        Statement stat = con.createStatement();
        String sql = "select id from perfume order by id asc";      
        ResultSet res = stat.executeQuery(sql);                             
        while(res.next()){
            Object[] ob = new Object[3];
            ob[0] = res.getString(1);
            jComboBox5.addItem(ob[0]);                                     
        }
        } catch (Exception e) {
            JOptionPane.showMessageDialog(null, e);
    }
}


private void showCBdata(){
    try {
        Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/shop","root","");
        Statement stat = con.createStatement();
        String sql = "select name from perfume where id='"+jComboBox5.getSelectedItem()+"'";  
        ResultSet res = stat.executeQuery(sql);

    while(res.next()){
        Object[] ob = new Object[3];
        ob[0]=  res.getString(1);            
        jTextField8.setText((String) ob[0]);
    }
    } catch (Exception e) {
        JOptionPane.showMessageDialog(null, e);
    }
}


//call method
private void jComboBox5ActionPerformed(java.awt.event.ActionEvent evt) {                                           
    showCBdata();
}

你能帮帮我吗？

谢谢你..

Answer 1

你可以这样做它会自动刷新 combobox

try {
            comboBox.removeAllItems();

            sql = "SELECT * FROM `table_name`";
            rs = stmnt.executeQuery(sql);

        while (rs.next()) {
            String val = rs.getString("column_name");
            comboBox.addItem(val);
        }
    } catch (SQLException ex) {
        Logger.getLogger(DefineCustomer.class.getName()).log(Level.SEVERE, null, ex);
    }

removeAllItems(); 方法将清除组合框以确保不重复值。
您不需要创建一个单独的 Object 来添加到 jComboBox 中，您也可以添加 String。