NumberLong数据查询如何正确管理Springboot？

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>

@Configuration
public class MongoConfig {

    @Value("${spring.data.mongodb.host}")
    private String host;

    @Value("${spring.data.mongodb.port}")
    private int port;

    @Value("${spring.data.mongodb.database}")
    private String database;

    @Bean
    public MongoClient mongoClient() {
        return new MongoClient(host, port);
    }

    @Bean
    public MongoTemplate mongoTemplate() {
        return new MongoTemplate(mongoClient(), database);
    }
}

@Autowired
private MongoTemplate mongoTemplate;

public List<User> findAdultUsers() {
    Query query = new Query(Criteria.where("age").gte(new NumberLong(18)));
    return mongoTemplate.find(query, User.class, "users");
}