你可以利用 com.mongodb.client.model.UpdateOneModel ，因此mongo将尝试更新现有文档的一个（或多个）字段。

MongoDatabase db = client.getDatabase("test");
MongoCollection<Document> collection = db.getCollection("test");

List<UpdateOneModel<Document>> updateList = List.of(
                new UpdateOneModel<>(new Document(Map.of("col1", "val1")), Updates.set("field", "1")),
                new UpdateOneModel<>(new Document(Map.of("col1", "val2")), Updates.set("field", "2")));
BulkWriteOptions options = new BulkWriteOptions().ordered(false);
collection.bulkWrite(updateList, options);

如果你需要一种上进的行为，你可以使用 com.mongodb.client.model.ReplaceOneModel 与 ReplaceOptions.upsert(true) :

ReplaceOptions replaceOptions = new ReplaceOptions().upsert(true);
List<ReplaceOneModel<Document>> replaceList = List.of(
                new ReplaceOneModel<>(new Document(Map.of("col1", "val3")), new Document(Map.of("col1", "val3", "field", "1")), replaceOptions),
                new ReplaceOneModel<>(new Document(Map.of("col1", "val4")), new Document(Map.of("col1", "val4", "field", "2")), replaceOptions));
collection.bulkWrite(replaceList, options);