private String bytesToString(byte[] bytes, int offset, int length)
            throws UnsupportedEncodingException, StringIndexOutOfBoundsException {
        return new String(bytes, offset, length, encoding);
    }
private String bytesToString ( byte [ ] bytes , int offset , int length ) throws UnsupportedEncodingException , StringIndexOutOfBoundsException { return new String ( bytes , offset , length , encoding ) ; }
The function to convert a sub-range of an array of bytes into a string.

@param bytes  a string represented by an array of bytes.
@param offset the initial offset
@param length the length
@return the conversion result string.
@throws UnsupportedEncodingException    when unknown encoding.
@throws StringIndexOutOfBoundsException when invalid offset and/or length.