try {
    // Convert from Unicode to UTF-8
    String string = "\u003c";
    byte[] utf8 = string.getBytes("UTF-8");

    // Convert from UTF-8 to Unicode
    string = new String(utf8, "UTF-8");
} catch (UnsupportedEncodingException e) {
}

引用 http://www.exampledepot.com/egs/java.lang/unicodetoutf8.html