java仿百度假分页代码实现的详解

 Integer start = (pageNum - 1) * pageSize;    Integer end = pageSize;    List<entity> entityList;        //调用mapper查询数据库    entityList = entityPOMapper.query(start, end);    SimplePageInfo simplePageInfo = SimplePageInfo.of(entityList );    simplePageInfo.setNumber(pageNum);    simplePageInfo.setPageSize(pageSize);// 查询出来数据等于size,总数据量加一，页数加一    if (entityList .size() == pageSize) {      Integer totalElements = (pageNum * pageSize) + 1;      Integer pages = pageNum + 1;      simplePageInfo.setTotalElements(totalElements);      simplePageInfo.setPages(pages);    } else {    //数据不够size      Integer totalElements = ((pageNum - 1) * pageSize + entityList .size());      Integer pages = pageNum;      simplePageInfo.setTotalElements(totalElements);      simplePageInfo.setPages(pages);    }    return simplePageInfo;}

<select .............>    select..    from ...    where ...    LIMIT #{start}, #{end}  </select>