Spring Data MongoDB:如何使用aggregate和SetIntersection获取两个列表之间的交集

import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.aggregation.*;
import org.springframework.data.mongodb.core.query.Criteria;

import java.util.List;

public class IntersectionQueryExample {
    
    private final MongoTemplate mongoTemplate;
    
    public IntersectionQueryExample(MongoTemplate mongoTemplate) {
        this.mongoTemplate = mongoTemplate;
    }

    public List<String> getIntersection(List<String> list1, List<String> list2) {
        Aggregation aggregation = Aggregation.newAggregation(
                Aggregation.match(Criteria.where("fieldName").in(list1)),
                Aggregation.group("fieldName"),
                Aggregation.project("_id").and("fieldName").previousOperation(),
                Aggregation.setIntersection(list2).as("intersection")
        );

        AggregationResults<Document> results = mongoTemplate.aggregate(aggregation, "collectionName", Document.class);
        List<Document> documents = results.getMappedResults();
        // 获取交集结果
        return documents.stream()
                .map(document -> document.getString("fieldName"))
                .collect(Collectors.toList());
    }
}