@Override
  public DropPartitionMessage getDropPartitionMessage(String messageBody) {
    try {
      return mapper.readValue(messageBody, JSONDropPartitionMessage.class);
    }
    catch (Exception exception) {
      throw new IllegalArgumentException("Could not construct DropPartitionMessage.", exception);
    }
  }
MessageDeserializer implementation, for deserializing from JSON strings.
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/messaging/json/JSONMessageDeserializer.java