没有选择jTable行时如何显示消息？

Question

I have a jButton and when it is clicked currently I can select multiple rows and I am able to delete all of them. I am trying to make a message pop up if no row is selected to warn the user. I tried different things, but I couldn't manage it in the end unfortunately.

private void silButtonActionPerformed(java.awt.event.ActionEvent evt) {                                          
    try {
        int[] selectedItems = jTable2.getSelectedRows();
        for (int i = 0; i < selectedItems.length; i++) {
            String cell = (jTable2.getModel().getValueAt(selectedItems[i], 0)).toString();
            System.out.println(cell);
            String query="DELETE FROM Musteriler WHERE id="+cell+"";
            PreparedStatement pst = connection.prepareStatement(query);
            int rs = pst.executeUpdate();
        }

        loadTable();
        cleanFields();
    } catch (Exception e) {
        System.out.println(e);
    }
}           

Answer 1

Simply just test that selectedItems length is zero or not:

if(selectedItems == null || selectedItems.length() < 1) {
    showPopup();
}

Answer 2

API reference:

public int[] getSelectedColumns​()

Returns: an array of integers containing the indices of all selected columns, or an empty array if no column is selected.

Basically you should check if the selectedItems is empty and show your modal dialog.