Yes.
Here is a section of the previous example:
public class percentFat extends JFrame implements ActionListener
{
JLabel title = new JLabel("Percent of Calories from Fat");
JLabel fatLabel = new JLabel("Enter grams of fat: ");
JLabel calLabel = new JLabel("Enter total calories: ");
JLabel perLabel = new JLabel("Percent calories from fat: ");
JTextField inFat = new JTextField( 7 );
JTextField inCal = new JTextField( 7 );
JTextField outPer = new JTextField( 7 );
JButton doit = new JButton("Do It!");
. . . . .