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!"); . . . . .