Simple notepad

//a simple notepad witch can open a file, save a file, clear the text and exit the program

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintStream;
import java.util.Scanner;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;

@SuppressWarnings("serial")
public class SimpleNotepad extends JFrame implements ActionListener {

    private final JButton btnExit, btnClear, btnSave, btnLoad;
    private final JTextArea txaInput;
    private final JTextField txtFileName;

    public SimpleNotepad(int x, int y){
        super("SimpleNotepad");

        final JPanel JPanelTop, JPanelBottom;
        final JScrollPane  JScrollCenter;
        //Deklarerer
        btnExit = new JButton("Exit");
        btnClear = new JButton("Clear");
        btnSave = new JButton("Save");
        btnLoad = new JButton("Load");
        txaInput = new JTextArea();
        txtFileName = new JTextField();

        //paneler
        JPanelTop = new JPanel(new GridLayout(1, 2));
        JPanelBottom = new JPanel(new GridLayout(1, 4));

        //legger til scroll på txaInput
        JScrollCenter = new JScrollPane(txaInput);

        //add til øvre panel
        JPanelTop.add(new JLabel("Filnavn: "));
        JPanelTop.add(txtFileName);

        //add til nedre panel
        JPanelBottom.add(btnLoad);
        JPanelBottom.add(btnSave);
        JPanelBottom.add(btnClear);
        JPanelBottom.add(btnExit);

        //textwrapping
        txaInput.setLineWrap(true);
        txaInput.setWrapStyleWord(true);

        //Lytter etter forandring
        btnExit.addActionListener(this);
        btnClear.addActionListener(this);
        btnSave.addActionListener(this);
        btnLoad.addActionListener(this);
        txtFileName.addActionListener(this);

        //legger til panelene
        add(JPanelTop, BorderLayout.NORTH);
        add(JScrollCenter, BorderLayout.CENTER);
        add(JPanelBottom, BorderLayout.SOUTH);

        setSize(x,y);
        setVisible(true);

        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

    public static void main(String[] args) {
        //sender inn størrelsen på skjermen
        new SimpleNotepad(500,400);

    }

    public void actionPerformed(ActionEvent e) {

        final Object source = e.getSource();
        final File file = new File(txtFileName.getText());

        //Exitknapp
        if(source == btnExit){
            System.exit(0); // avslutter
        }
        //clearKnapp
        else if(source == btnClear){
            txaInput.setText(null); //fjerner teksten
            txtFileName.setText(null);
        }
        //saveknapp
        else if(source == btnSave){

            PrintStream pS = null;
            if(!file.exists()){ //tester om filen ikke finnes
                try {
                    file.createNewFile(); //oppretter ny fil
                } catch (Exception e2) {}
            }

            try {
                pS = new PrintStream(file); //henter inn file som skal skrives til
            } catch (FileNotFoundException e1) {
                JOptionPane.showMessageDialog(null, "File can not be null"); //sier fra at du har gjort feil
            }

            if(pS != null){
                pS.print(txaInput.getText()); // skriver til filen
                pS.close(); //lukker filen
            }
        }
        //loadknapp, eller enter på filnavn txtfeltet
        else if(source == btnLoad || source == txtFileName){
            String tempText = "";
            Scanner filScanner = null;
            if(file.exists()){ //tester filen finnes
                try {
                    filScanner = new Scanner(file); // henter inn filen som skal lese fra
                } catch (FileNotFoundException e1) {}

                while(filScanner.hasNextLine()){ //skjekker om det er flere linjer igjen
                    tempText += filScanner.nextLine() + "\n"; //legger til hver linje inn i en string
                }

                txaInput.setText(tempText);// legger stingen inn i tekstarea
                filScanner.close(); // lukker filen
            }else{
                JOptionPane.showMessageDialog(null, "File do not exists");//sier fra hvis filen ikke finnes
            }
        }
    }
}