[Java] 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>