java - 无法使用java执行mongo db聚合查询，

Question

我正在第一次使用 java 为 mongo db 编写聚合查询。我无法将我之前编写的 shell 查询转换为 java 格式。我面临一些问题。下面是我已经编写的 shell 查询，它工作正常。

房间日期设定。

{
 "_id": ObjectId("571c5724db62826826d28d08"),
"conversationId": "6puebew70kke29",
"userId": "600",
"firstName": "Test",
"profileImagePath": "",
"created": ISODate("2016-04-24T05:18:28.753Z"),
"__v": 0
}
{
   "_id": ObjectId("571c5724db62826826d28d09"),
"conversationId": "6puebew70kke29",
"userId": "900",
"firstName": "User",
"profileImagePath": "",
"created": ISODate("2016-04-24T05:18:28.754Z"),
"__v": 0
 }

  {
"_id": ObjectId("571c574edb62826826d28d0b"),
"conversationId": "fsny11z742kpgb9",
"userId": "600",
"firstName": "FitTest",
"profileImagePath": "",
"created": ISODate("2016-04-24T05:19:10.192Z"),
"__v": 0
 }

  {
"_id": ObjectId("571c574edb62826826d28d0c"),
"conversationId": "fsny11z742kpgb9",
"userId": "800",
"firstName": "Dev",
"profileImagePath": "",
  "created": ISODate("2016-04-24T05:19:10.193Z"),
"__v": 0
    }



 rooms.aggregate([{
        $match: {
            type: 'PRIVATE'
        }
    }, {
        $group: {
            _id: '$conversationId',
            users: {
                $push: '$userId'
            }
        }
    }, {
        $match: {
            users: {
                $all: [friendProfileData.id, userprofileData.id]
            }
        }
    }, ]

上述查询的 Java 代码。

 Aggregation agg = newAggregation(
            match(Criteria.where("type").is("PRIVATE")),
            group("_id", "conversationId"),
            group("users").push("userId").as("users")
            );

    AggregationResults<Rooms> groupResults = mongoOps.aggregate(agg,   "rooms", Rooms.class);
    List<Rooms> result = groupResults.getMappedResults();

无法完全完成它，但我不知道如何编写一些表达式。感谢您的帮助。

Answer 1

我做了一个假设，因为我不确定最后一个“匹配”中的“friendProfileData”和“userprofileData”属性。

您可以根据您的要求相应地更改“Filters.all”语句。否则，此代码应该满足您的要求，并且它可以与“MongoDB 3.2.0”和“Mongo Java Driver 3.2.2 Jar”一起正常工作。

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.bson.Document;
import org.bson.conversions.Bson;

import com.mongodb.MongoClient;
import com.mongodb.client.AggregateIterable;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.model.Accumulators;
import com.mongodb.client.model.Aggregates;
import com.mongodb.client.model.Filters;

public static void main(String[] args) {
        MongoClient client = new MongoClient();
        MongoDatabase database = client.getDatabase("localhost");

        List<Bson> aggregateList = new ArrayList<>();

        aggregateList.add(Aggregates.match(Filters.eq("type", "PRIVATE")));
        aggregateList.add(Aggregates.group("$conversationId", Accumulators.push("users", "$userId")));
        aggregateList.add(Aggregates.match(Filters.all("users", Arrays.asList("1", "800"))));

        AggregateIterable<Document> mongoCollectionList = database.getCollection("rooms")
                .aggregate(aggregateList);

        MongoCursor<Document> mongoCursor = mongoCollectionList.iterator();

        while (mongoCursor.hasNext()) {
            System.out.println(mongoCursor.next());

        }

    }

Maven 依赖项:-

上面的工作正常与下面的 Maven 依赖项。

<dependency>
    <groupId>org.mongodb</groupId>
    <artifactId>mongo-java-driver</artifactId>
    <version>3.2.2</version>
</dependency>

请注意，如果您使用以下 jar，则上述可能不起作用:-

<dependency>
    <groupId>org.mongodb</groupId>
    <artifactId>mongodb-driver</artifactId>
    <version>3.2.2</version>
</dependency>