MongoDB分页以及复杂条件查询例子

此处MongoDB的复杂的分页采用d调用MongoTemplate来实现

    springboot中application.yml 配置

    spring
      data:
        mongodb:
          uri: mongodb://username:password@host:port/database

    基本的查询能够经过 spring data jpa来实现,for example

        public interface TestDao extends MongoRepository<Test,String> {
        }

1.编写MongoDB分页查询工具类，查询总条数以及分页的方法

 /**
     * 查询总条数
     * @param operations
     * @param collectionName
     * @param clazz
     * @return
     */
    public long getTotalCount(List<AggregationOperation> operations,String collectionName,Class clazz){
        Aggregation aggregationCount = Aggregation.newAggregation(operations);
        List mappedResults = mongoTemplate.aggregate(aggregationCount, collectionName, clazz).getMappedResults();
        if(null == mappedResults){
            return 0;
        }else{
            return mappedResults.size();
        }
    }

    /**
     * collection的信息分页查询
     * @param page
     * @param pageSize
     * @param sorts
     * @param operations
     * @param collectionName
     * @param clazz
     * @return
     */
    public Page<T> getPageList(int page, int pageSize, Sort sorts, List<AggregationOperation> operations,
                    String collectionName, Class clazz){
        long totalCount = getTotalCount(operations,collectionName,clazz);
        operations.add(Aggregation.skip((long) (page-1) * pageSize));
        operations.add(Aggregation.limit(pageSize));
        Aggregation aggregation = Aggregation.newAggregation(operations);
        AggregationResults<FormControlsDTO> results = mongoTemplate.aggregate(aggregation,collectionName,clazz);
        Pageable pageable = PageRequest.of(page-1, pageSize, sorts);
        return new PageImpl(results.getMappedResults(), pageable, totalCount);
    }
    
    

2. 注入工具类，并使用聚合函数来添加设置查询条件

    
    Sort sorts = null;
    List<AggregationOperation> operations = new ArrayList<>();
    
    //设置排序
    sorts = new Sort(Sort.Direction.ASC,sort);
    operations.add(Aggregation.sort(Sort.Direction.ASC, sort));
            
    //精确匹配
    operations.add(Aggregation.match(Criteria.where("id").is(id)));
    
    //使用正则表达式模糊匹配
    Pattern pattern = Pattern.compile("^.*"+keyword+".*$", Pattern.CASE_INSENSITIVE);
    operations.add(Aggregation.match(Criteria.where(LpConstants.KEYWORD).regex(pattern)));

//and  or 组合 

Criteria criteria1 = new Criteria().orOperator(Criteria.where("a").regex(pattern),
                Criteria.where("b").regex(pattern));
Criteria c = new Criteria().andOperator(new Criteria().where("id").is(id),
                criteria1);
operations.add(Aggregation.match(c));

   
    //日期比较
    operations.add(Aggregation.match(Criteria.where("create_time").gte(format.parse(beginTime))));
    operations.add(Aggregation.match(Criteria.where("create_time").lte(format.parse(endTime))));

    Page<Test> page = mongoDao.getPageList(page,pageSize,sorts,operations,"collectionName",Test.class);