Question

我们使用mongo-java-driver 3.0.4的代码曾经像 -

DBCollection dbCollection = mongoClient.getDB(databaseName).getCollection(collectionName);
QueryBuilder queryBuilder = new QueryBuilder();
/** queryBuilder.put() for building the query */
DBCursor dbCursor = dbCollection.find(queryBuilder.get());
while(dbCursor.hasNext()) {
    DBObject dbObject = dbCursor.next();
    // add entries to a list of TDocument type
}

将其转换为mongo-java-driver 3.3.0，我最终得到了这个 -

MongoCollection<TDocument> collection = database.getCollection(collectionName, TDocument.class); //where TDocument is custom document class of ours
QueryBuilder queryBuilder = new QueryBuilder();
/** queryBuilder.put() for building the query */
FindIterable<TDocument> tDocumentList = collection.find(queryBuilder.get()); //this is not compiling
for (TDocument element : tDocumentList) {
    names.add(element.getName()); //addition to some list of TDocument type
}

但关键是我仍然无法编译我已定义的MongoDB集合上find操作的源代码。

这里有什么需要纠正的？我想坚持任何有助于将mongo升级到3.3.0 +的首选实现。

编辑 - 我的TDocument类（名称与lib名称不同）类是一个简单的POJO -

public class TDocType {

    private TDocType() {
    }

    String one;

    @NotNull
    String name;

    String third;

    String fourth;

    // getter and setter for all the above
}

Answer 1

投向Bson。

 FindIterable<TDocument> tDocumentList = collection.find((Bson)queryBuilder.get());

更新:: 更改为使用Mongo 3.3.0中的过滤器

Bson filter = Filters.eq("field", "value");
FindIterable<TDocument> tDocumentList = collection.find(filter);

Answer 2

您可以使用org.bson.Document替换查询构建器，如下所示：

Document query = new Document();
query.put(parameterName, parameterValue);

然后

FindIterable<TDocument> tDocumentList = collection.find(query); //this is not compiling

使用Mongo 3.3.0中的QueryBuilder查询Mongo Collection

2 个答案: