如何在MongoRepository中查找不同的数据

import org.springframework.data.mongodb.core.aggregation.Aggregation;
import org.springframework.data.mongodb.core.aggregation.AggregationResults;
import org.springframework.data.mongodb.core.aggregation.GroupOperation;
import org.springframework.data.mongodb.core.aggregation.TypedAggregation;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.repository.MongoRepository;

import java.util.List;

public interface MyRepository extends MongoRepository<MyEntity, String> {

    default List<String> findDistinctData() {
        GroupOperation groupOperation = Aggregation.group("data");
        TypedAggregation<MyEntity> aggregation = Aggregation.newAggregation(MyEntity.class, groupOperation);

        AggregationResults<DistinctData> results = getMongoOperations().aggregate(aggregation, DistinctData.class);
        return results.getMappedResults().stream().map(DistinctData::getData).collect(Collectors.toList());
    }

    class DistinctData {
        private String data;

        public String getData() {
            return data;
        }

        public void setData(String data) {
            this.data = data;
        }
    }
}