SpringBoot使用MongoTemplate详解

1.pom.xml引入Jar包

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

2.MongoDbHelper封装

/**
 * MongoDB Operation class
 * @author HyoJung
 * @date 2024-03-05
 */
public class MongoDbHelper {
    @Autowired
    private MongoTemplate mongoTemplate;
    /**
     * Save Individual Objects
     *
     * @param t 实体类参数
     * @param <T> 实体类
     * @return
     */
    public <T> T save(T t) {
        return mongoTemplate.insert(t);
    }

    /**
     * Store the object to the specified collectionName
     * @param objectToSave
     * @param collectionName 类似SQL数据库的表名
     * @param <T>
     * @return
     */
    public <T> T save(T objectToSave, String collectionName){
        return mongoTemplate.insert(objectToSave,collectionName);
    }

    /**
     * 批量存储
     *
     * @param list
     * @param collectionName
     * @return
     */
    public <T> Collection<T> batchSave(Collection<T> list, String collectionName) {
        return mongoTemplate.insert(list,collectionName);
    }

    /**
     * Query Data
     *
     * @param query
     * @param tClass
     * @param <T>
     * @return
     */
    public <T> List<T> find(Query query, Class<T> tClass) {
        return mongoTemplate.find(query, tClass);
    }

    /**
     * Collection specified by query data
     *
     * @param query
     * @param tClass
     * @param <T>
     * @return
     */
    public <T> List<T> find(Query query, Class<T> tClass, String collectionName) {
        return mongoTemplate.find(query, tClass,collectionName);
    }

    /**
     * 分页查询
     * @param query query criteria
     * @param pageNum Current Page
     * @param pageSize Number of entries per page
     * @param sortField Sorted Field
     * @param sortType 1:asc;0:desc
     * @param tClass to class
     * @param collectionName collection name
     * @param <T>
     * @return
     */
    public <T> MongoPage findByPage(Query query,int pageNum,int pageSize,String sortField,int sortType, Class<T> tClass, String collectionName) {
        int count = (int) mongoTemplate.count(query, tClass, collectionName);
        if(sortType==1){
            query.with(Sort.by(Sort.Order.asc(sortField)));
        }else {
            query.with(Sort.by(Sort.Order.desc(sortField)));
        }
        //Set starting number
        query.skip((pageNum - 1) * pageSize);
        //Set the number of queries
        query.limit(pageSize);
        //Query the current page data set
        List<T> taskList = mongoTemplate.find(query, tClass,collectionName);
        int size=count % pageSize == 0 ? count / pageSize : count / pageSize + 1;
        MongoPage page=new MongoPage();
        page.setTotal(count);
        page.setSize(size);
        page.setData(taskList);
        return page;
    }

    /**
     * 查询前几条数据
     * @param query
     * @param limitNum 前几条
     * @param sortField 排序字段
     * @param sortType 0:倒序；1:正序
     * @param tClass
     * @param collectionName
     * @param <T>
     * @return
     */
    public <T> List<T> findTop(Query query,Integer limitNum,String sortField,int sortType, Class<T> tClass, String collectionName){
        if(sortType==1){
            query.with(Sort.by(Sort.Order.asc(sortField)));
        }else {
            query.with(Sort.by(Sort.Order.desc(sortField)));
        }
        query.limit(limitNum);
        return mongoTemplate.find(query, tClass,collectionName);
    }

    /**
     * 查询一条数据
     * @param query
     * @param sortField
     *