public static String toString(Reader input) throws IOException {
        StringWriter sw = new StringWriter();
        copy(input, sw);
        return sw.toString();
    }
Get the contents of a <code>Reader</code> as a String.
<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 String
@throws NullPointerException if the input is null
@throws IOException          if an I/O error occurs
pay-java-common/src/main/java/com/egzosn/pay/common/util/IOUtils.java