UTF-8 byte[] to String

Look at the constructor for String

String str = new String(bytes, StandardCharsets.UTF_8);

And if you're feeling lazy, you can use the Apache Commons IO library to convert the InputStream to a String directly:

String str = IOUtils.toString(inputStream, StandardCharsets.UTF_8);

To convert utf-8 data, you can't assume a 1-1 correspondence between bytes and characters. Try this:

String file_string = new String(bytes, "UTF-8");

(Bah. I see I'm way to slow in hitting the Post Your Answer button.)

To read an entire file as a String, do something like this:

public String openFileToString(String fileName) throws IOException
{
    InputStream is = new BufferedInputStream(new FileInputStream(fileName));

    try {
        InputStreamReader rdr = new InputStreamReader(is, "UTF-8");
        StringBuilder contents = new StringBuilder();
        char[] buff = new char[4096];
        int len = rdr.read(buff);
        while (len >= 0) {
            contents.append(buff, 0, len);
        }
        return buff.toString();
    } finally {
        try {
            is.close();
        } catch (Exception e) {
            // log error in closing the file
        }
    }
}

Java String class has a built-in-constructor for converting byte array to string.

byte[] byteArray = new byte[] {87, 79, 87, 46, 46, 46};

String value = new String(byteArray, "UTF-8");