RTEditor/src/main/java/com/onegravity/rteditor/utils/io/IOUtils.java
public static byte[] toByteArray(Reader input, String encoding) throws IOException {
        return toByteArray(input, Charsets.toCharset(encoding));
    }
public static byte[] toByteArray(Reader input, String encoding) throws IOException {
        return toByteArray(input, Charsets.toCharset(encoding));
    }
Get the contents of a <code>Reader</code> as a <code>byte[]</code>
using the specified character encoding.
<p/>
Character encoding names can be found at
<a href="http://www.iana.org/assignments/character-sets">IANA</a>.
<p/>
This method buffers the input internally, so there is no need to use a
<code>BufferedReader</code>.

@param input    the <code>Reader</code> to read from
@param encoding the encoding to use, null means platform default
@return the requested byte array
@throws NullPointerException        if the input is null
@throws IOException                 if an I/O error occurs
@throws UnsupportedCharsetException thrown instead of {@link UnsupportedEncodingException} in version 2.2 if the encoding is not
supported.
@since 1.1