如何将mysql中的数据插入组合框？

Question

我的代码在这里出了什么问题？

我试图将mysql中的数据插入netbean中的组合框

private void btnSandoghMousePressed(java.awt.event.MouseEvent evt) {                                        
    try {
        String query = "SELECT `AccountType` FROM `account`"; 
        con = Connect.ConnectDB();
        PreparedStatement stm = con.prepareStatement(query); 
        pst = con.prepareStatement(query);                
        ResultSet rs = pst.executeQuery(query);
        ArrayList<String> groupNames = new ArrayList<String>(); 
        while (rs.next()) { 
            String groupName = rs.getString(4); 
            groupNames.add(groupName);
        } 
        DefaultComboBoxModel model = new DefaultComboBoxModel(groupNames.toArray());
        cmbSemetarID.setModel(model);
        rs.close();    
    } catch (SQLException e) {
    System.err.println("Connection Error! it's about date");
    }
}

Answer 1

有时您会尝试以这种方式使用Model或使用Vector时遇到问题。最好尝试做类似的事情，

  private void btnSandoghMousePressed(java.awt.event.MouseEvent evt){                                        
    try {
        String query = "SELECT `AccountType` FROM `account`"; 
        con = Connect.ConnectDB();
        PreparedStatement stm = con.prepareStatement(query); 
        pst = con.prepareStatement(query);                
        ResultSet rs = pst.executeQuery(query);
        DefaultComboBoxModel model = new DefaultComboBoxModel();
        while (rs.next()) { 
            String groupName = rs.getString(4); 
            model.add(groupName);
        } 

        cmbSemetarID.setModel(model);
        rs.close();    
    } catch (SQLException e) {
    System.err.println("Connection Error! it's about date");
    }
}

Answer 2

也许你的groupNames.toArray（）方法不适合DefaultComboBoxModel（）构造函数。

您可以尝试将项目逐个放入ArrayList中：

DefaultComboBoxModel model = new DefaultComboBoxModel();
for(String groupname : groupNames) 
{
  model.addElement(groupname);
}
cmbSemetarID.setModel();

这就是我如何填充我的组合框。