code: public Object readValue(InputStream is, Class<Object> clazz) {
  		try {
  			return this.mapper.readValue(is, clazz);
  		}
  		catch (Exception e) {
  			LogFactory.getLog(JsonHandler.class).info("deserialize json to object", e);
  			return null;
  		}
  	}
docs: Converts a JSON string into an object. The input is read from an InputStream. In
  case of an exception returns null and logs the exception.
  
  @param is a InputStream
  @param clazz class of object to create
  @return the converted object, null if there is an exception