public static byte[] encode(String s) {
        return s == null ? new byte[0] : s.getBytes(RpcConstants.DEFAULT_CHARSET);
    }
@author <a href="mailto:zhanggeng.zg@antfin.com">GengZhang</a>
@since 5.4.0
codec/codec-api/src/main/java/com/alipay/sofa/rpc/codec/common/StringSerializer.java