Java programing Help?

I have a Java project where I have to build a GUI to convert Celsius to Fahrenheit and vise versa.

I have made that program:

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

public class p8 extends JFrame //creates class p8 (extention on JFrame)

{

private JLabel TempL, ResultsL; //initates TempL and ResultsL (JLables

private JTextField inputTF, resultsTF; //initates inputTF nad resultsTF (JTextFields)

private JButton c2fB, f2cB; //initates c2fB and f2cB (JButtons)

private C2FButtonHandler C2FHandler; //initates C2FButtonHandler

private F2CButtonHandler F2CHandler; //initates F2CButtonHandler

public p8() //begins public class p8

{

Container pane = getContentPane();

pane.setLayout(new GridLayout(3,2)); //sets content pane to a 3 row x 2 column grid

TempL = new JLabel("Temperature:"); //creates new JLabel named Temperature

ResultsL = new JLabel("Results:"); //creates new JLable named Results

inputTF = new JTextField("0",10); //creates new JTextField 10 columns wide and set to zero

resultsTF = new JTextField("",40); //creates new JTextField 40 columns wide with no initial value

c2fB = new JButton("Celsius to Fahrenheit"); //creates new JButton names Celsius to Fahrenheit

f2cB = new JButton("Fahrenheit to Celsius"); //creates new JButton named Fahrenheit to Celsius

C2FHandler = new C2FButtonHandler(); //creates a new ButtonHandler (C2F) and calls it C2FHandler

c2fB.addActionListener(C2FHandler); //waits for c2fB to be pushed and uses C2FHandler when that happens

F2CHandler = new F2CButtonHandler(); //creates new ButtonHandler (F2C) and calls it F2CHandler

f2cB.addActionListener(F2CHandler); //waits for f2cB to be pushed and uses F2CHandler when that happens

pane.add(TempL); //adds TempL to emplt pane in spot 1,1

pane.add(inputTF); //adds inputTF to pane in spot 1,2

pane.add(c2fB); //adds c2fB to pane in spot 2,1

pane.add(f2cB); //adds f2cB to pane in spot 2,2

pane.add(ResultsL); //adds ResultsL to pane in spot 3,1

pane.add(resultsTF); //adds resultsTF to pane in spot 3,2

resultsTF.setEditable(false); //enables user from editing resultsTF

setTitle("Celsius and Fahrenheit conversion"); //assigns title to pane

setSize(375,120); // sets size for pane

setDefaultCloseOperation(EXIT_ON_CLOSE); //sets close operations for pane

setVisible(true); //turns on pane visibility

}

private class C2FButtonHandler implements ActionListener //implements ActionListber for button c2fB

{

public void actionPerformed(ActionEvent e) //method to preform action for button c2fB

{

int Ctemp, Ftemp; //defines integers Ctemp and Ftemp

Ctemp=Integer.parseInt(inputTF.getText()); //gets input from user converts it to an int and defines it as Ctemp

Ftemp= (Ctemp)*9/5+32; //calculates Ftemp

resultsTF.setText(+Ctemp+" Celsius is"+Ftemp+" Fahrenheit"); //display results

}

}

private class F2CButtonHandler implements ActionListener //implements ActionListner for Button f2cB

{

public void actionPerformed(ActionEvent e) //method to preforme action for button f2cB

{

int Ctemp, Ftemp; //defines integers Ctemp and Ftemp

Ftemp=Integer.parseInt(inputTF.getText()); //gets input from user converts it to an int and defines it as Ftemp

Ctemp= ((Ftemp)-32)*5/9; //calculates Ctemp

resultsTF.setText(+Ftemp+" Fahrenheit is"+ Ctemp+" Celsius"); //display results

}

}

public static void main(String[] args) //begins main method

{

p8 window = new p8(); //opens new window p8()

}

}

however there is an extra credit portion that I need help with:

to gain extra credit I have to use try/catch to only allow numeric values to be accepted and alert the user when an invalid entry has been entered.

I have this example out of the book

public static int getNumber()

throws InputMismatchException

{

int num;

try

{

System.out.print("Enter an Integer:");

num=kb.nextInt();

System.out.println();

return num;

}

catch (InputMismatchException imeRef)

{

throw imeRef;

}

}

but I dont know how to get them to work together, or how exactly try/catch works.

need help please