也许您应该在决定再次发布数据之前清除JTable模型的行.代替您的:

Perhaps you should Clear your JTable model of its rows before you decide to reissue the data again. Instead of your:

if (deftm.getRowCount() != 0) {
    deftm.setRowCount(0);
}

代码，也许使用简单的 clearTable()方法，例如:

code, perhaps use a simple clearTable() method like:

private void clearJTable(DefaultTableModel yourTableModel) {
    while (yourTableModel.getRowCount() > 0) {
        for (int i = 0; i < yourTableModel.getRowCount(); i++) {
            yourTableModel.removeRow(i);
        }
    }
}

，然后在您的代码中:

DefaultTableModel deftm = (DefaultTableModel) allTable.getModel();

    clearJTable(deftm);

    stm = (Statement) conn.createStatement();
    ResultSet rs = stm.executeQuery("select * from customerregister.curtain inner join curtainrel on curtain.code = curtainrel.curtainCode;");
    while (rs.next()) {
        String shifra = rs.getString("code");
        String ngjyra = rs.getString("color");
        String emri = rs.getString("name");
        double cmimi = rs.getDouble("price");
        ....................................
        ....................................
        ....................................