if else wont work as it should JAVA

I am trying to make the if statement work but I dont know how's the right way to express it.

Button button_2 = new Button("Delete");
button_2.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {

Here I get the selection of the row and column which I intend to manipulate later.

        int column =0;
        int row = table_1.getSelectedRow(); 
        String id= table_1.getModel().getValueAt(row, column).toString();

                if (id==null) { // won't work as it should ? 
                JOptionPane.showMessageDialog(null, "Please select a row to delete!");


                  }else {


                        try{ 
                            String query3 = "DELETE FROM hostel_dtrm  WHERE id=?";
                            PreparedStatement pst= conn1.prepareStatement(query3);

                                pst.setString(1, id);
                                pst.executeUpdate();


                     // Printing the results after Row Deletion
                    String query2= "SELECT * FROM hostel_dtrm";
                    PreparedStatement psts= conn1.prepareStatement(query2);
                    ResultSet rs=psts.executeQuery();

                    table_1.setModel(DbUtils.resultSetToTableModel(rs));

                    // Closing stuff
                      pst.close();
                      rs.close();   

                  JOptionPane.showMessageDialog(null, "Row Deleted");

                   }catch(Exception err){
                        System.err.println(err);    
                        }

            }

        }
    });