RTEditor/src/main/java/com/onegravity/rteditor/utils/io/IOUtils.java
public static char[] toCharArray(Reader input) throws IOException {
        CharArrayWriter sw = new CharArrayWriter();
        copy(input, sw);
        return sw.toCharArray();
    }
public static char[] toCharArray(Reader input) throws IOException {
        CharArrayWriter sw = new CharArrayWriter();
        copy(input, sw);
        return sw.toCharArray();
    }
Get the contents of a <code>Reader</code> as a character array.
<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
@return the requested character array
@throws NullPointerException if the input is null
@throws IOException          if an I/O error occurs
@since 1.1