Do you actually have a text string?  Or just an array of bytes?  I would
have thought that any string you get back from reading the UTF-8 file
would be a proper Java 16-bit Unicode string.  Why isn't it?

How do you get your text string?

You must partition your problem.

1. make sure the file truly is encoded it UTF-8. See
http://mindprod.com/jgloss/encoding.html and use the encoding
recogniser.

2. read the UTF-8 file.  See http://mindprod.com/applet/fileio.html

3. verify that you indeed have the Unicode chars expected by dumping
them in decimal or hex.

4. make sure the font you are using supports those characters.  See
http://mindprod.com/applet/fontshower.html

Your Google-fu is too weak! Exercise it more!

--------------------------- 8< ---------------------------------
class CharacterEncodingTest {

    static final String FILENAME = "foo.txt";

    public static void main(String[] args) {
        try {
            writeMyUtf8File(FILENAME, "ééééé");
            final String text = readMyUtf8File(FILENAME);
            SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    new CharacterEncodingTest(text);
                }
            });
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    static void writeMyUtf8File(String name, String text)
            throws IOException {
        FileOutputStream fos = new FileOutputStream(name);
        Writer osr = new OutputStreamWriter(fos, "UTF-8");
        osr.write(text);
        osr.close();
    }

    static String readMyUtf8File(String name) throws IOException {
        FileInputStream fis = new FileInputStream(FILENAME);
        InputStreamReader isr = new InputStreamReader(fis, "UTF8");
        BufferedReader br = new BufferedReader(isr);
        String text = br.readLine();
        br.close();
        return text;
    }

    CharacterEncodingTest(String text) {
        JPanel p = new JPanel();
        p.add(new JLabel(text));

        JFrame f = new JFrame("Char Encoding Test");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(p);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }
}
--------------------------- 8< ---------------------------------