如何在JAVA中使用MongoDB聚合GroupOperation方法

<dependency>
    <groupId>org.mongodb</groupId>
    <artifactId>mongo-java-driver</artifactId>
    <version>3.12.12</version>
</dependency>

import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoClient;

MongoClient mongoClient = MongoClients.create("mongodb://localhost:27017");

import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoCollection;

MongoDatabase database = mongoClient.getDatabase("your_database_name");
MongoCollection<Document> collection = database.getCollection("your_collection_name");

import static org.springframework.data.mongodb.core.aggregation.Aggregation.*;

GroupOperation groupOperation = group("field1", "field2")
    .sum("field3").as("totalField3")
    .count().as("count");

import org.springframework.data.mongodb.core.aggregation.Aggregation;

Aggregation aggregation = newAggregation(groupOperation);

import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.aggregation.AggregationResults;

MongoTemplate mongoTemplate = new MongoTemplate(mongoClient, "your_database_name");
AggregationResults<Document> results = mongoTemplate.aggregate(aggregation, "your_collection_name", Document.class);
List<Document> documents = results.getMappedResults();