UTF Safe and Read

package my.utf.test;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.*;
import java.nio.charset.Charset;

/**
 * Created by ferdinand on 1/30/15.
 */
public class SwingUTF8 {

    public static void main(String[] args) {
        new SwingUTF8();
    }

    private JTextField dfKoreanInput = new JTextField();
    private JTextField dfKoreanOutput = new JTextField();
    private JButton pbTest = new JButton("Test");

    public SwingUTF8() {
        final JFrame mainFrame = new JFrame();
        mainFrame.setTitle("UTF-Test");
        mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel panel = new JPanel();
        panel.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
        panel.setLayout(new FlowLayout());
        panel.add(dfKoreanInput);
        panel.add(dfKoreanOutput);
        panel.add(pbTest);
        pbTest.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    saveData(dfKoreanInput.getText());
                    dfKoreanOutput.setText(readData());
                } catch (IOException ioe) {
                    JOptionPane.showMessageDialog(mainFrame, ioe.getMessage(), "Exception", JOptionPane.ERROR_MESSAGE);
                }
            }
        });
        mainFrame.setContentPane(panel);

        dfKoreanInput.setPreferredSize(new Dimension(200,50));
        dfKoreanOutput.setPreferredSize(new Dimension(200,50));
        pbTest.setPreferredSize(new Dimension(200,50));

        mainFrame.pack();
        mainFrame.setVisible(true);
    }

    public void saveData(String data) throws IOException {
        File file = new File("test.dat");
        if(file.exists()) file.delete();
        file.createNewFile();
        FileOutputStream fos = new FileOutputStream(file);
        fos.write(data.getBytes(Charset.forName("UTF-8")));
        fos.flush();
        fos.close();
    }

    public String readData() throws IOException {
        File file = new File("test.dat");
        FileInputStream fis = new FileInputStream(file);
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        byte[] buffer = new byte[100];
        int read = fis.read(buffer);
        while(read >= 0) {
            if(read > 0) {
                baos.write(buffer, 0, read);
            }
            read = fis.read(buffer);
        }
        try {
            return new String(baos.toByteArray(), "UTF-8");
        }
        finally{
            if(file.exists()) {
                file.delete();
            }
        }
    }

}