MongoDatasetDao.java 文件源码

@Override
public Dataset write(Dataset dataset) {
  // we populate this on first write and retain it thereafter
  if (isBlank(dataset.getId())) {
    dataset.setId(ObjectId.get().toString());
  }

  Observable<Document> observable =
      getCollection()
          .findOneAndReplace(
              Filters.eq("id", dataset.getId()),
              documentTransformer.transform(dataset),
              new FindOneAndReplaceOptions().upsert(true).returnDocument(ReturnDocument.AFTER));

  return documentTransformer.transform(Dataset.class, observable.toBlocking().single());
}