foo.java

  public <T> T deserialiseObject(final Buffer buffer, final HttpServerResponse response,
      final Class<T> clazz) {
    final ObjectMapper objectMapper = DatabindCodec.mapper();
    try {
      final T t = objectMapper.readValue(buffer.getBytes(), clazz);
    } catch (UnrecognizedPropertyException e) {
      sendUnrecognisedPropertyError(e.getPropertyName(), response);
      return null;
    } catch (MismatchedInputException e) {
      final int startIndex = e.getMessage().indexOf('\'');
      final int endIndex = e.getMessage().indexOf('\'', startIndex + 1);
      final String propertyName = e.getMessage().substring(startIndex + 1, endIndex);
      sendMissingPropertyError(propertyName, response);
      return null;
    } catch (JsonParseException e) {
      sendInvalidJsonError(response);
      return null;
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }