java中List分页的几种方法介绍

1.根据入参带分页参数进行sql查询分页

        Criteria criteria = new Criteria();
        //将dataAuto转成 factoryId brandId seriesId 等查询条件
        String dataAuth = "";
        TypeCaseHelper.dataAuto(criteria, dataAuth);
        // 设置分页信息
        ExtPager pager = new ExtPager();
        Integer startTure = start * pageSize;
        criteria.setMysqlPageSize(pageSize);
        criteria.setMysqlStart(startTure);
        // 排序信息
        if (StringUtils.isNotBlank(pager.getDir()) && StringUtils.isNotBlank(pager.getSort())) {
            criteria.setOrderByClause(pager.getSort() + " " + pager.getDir());
        }
        List<VhlAlarmStatusMgtEntity> listDistinct = getVhlAlarmStatusMgtEntities(vin, faultStatus, confirmStatus, startDateTime, endDateTime, sdf, sdfm, carTypeList, criteria);

对应的分页sql

 <select id="selectByExample" parameterType="Criteria" resultMap="BaseResultMap">
   select
   <include refid="Base_Column_List" />
   from status_mgt
   <where>
     <if test="condition.carTypeList != null and condition.carTypeList.size() > 0" >
       and car_type in
       <foreach collection="condition.carTypeList" item="item"  open="(" separator="," close=")">
         #{item}
       </foreach>
     </if>
     <if test="condition.startDateTime != null and condition.startDateTime!=''">
       and alarm_time >= str_to_date(#{condition.startDateTime,jdbcType=VARCHAR},'％Y-％m-％d ％H:％i:％S')
     </if>
     <if test="condition.endDateTime != null and condition.endDateTime!=''">
       and  str_to_date(#{condition.endDateTime,jdbcType=VARCHAR},'％Y-％m-％d ％H:％i:％S') >= alarm_time
     </if>
     and logic_flag = 1
   </where>
   order by alarm_time desc
   <if test="mysqlStart != null  and mysqlPageSize != null">
       limit #{mysqlStart}, #{mysqlPageSize}
   </if>

</select>

2.对所有list根据分页参数分页

        Criteria criteria1 = new Criteria();
        List<VhlAlarmStatusMgtEntity> listDistinctForCout = getVhlAlarmStatusMgtEntities(vin, faultStatus, confirmStatus, startDateTime, endDateTime, sdf, sdfm, carTypeList, criteria1);
        Integer count = listDistinctForCout.size(); // 记录总数
        Integer pageCount; // 页数
        if (count ％ pageSize == 0) {
            pageCount = count / pageSize;
        } else {
            pageCount = count / pageSize + 1;
        }
        int fromIndex; // 开始索引
        int toIndex; // 结束索引
        if (!pageCount.equals(start+1)) {
            fromIndex = start * pageSize;
            toIndex = fromIndex + pageSize;
            if(toIndex > count){
                fromIndex = (start-1) * pageSize;
                toIndex = count;
            }
        } else {
            fromIndex = start * pageSize;
            toIndex = count;
        }
        List<VhlAlarmStatusMgtEntity> pageList = listDistinctForCout.subList(fromIndex, toIndex);

3.PageHelper分页

     //开启分页
       PageHelper.startPage(Integer.parseInt(pageNum), Integer.parseInt(pageSize));

PageInfo<Map<String, String>> pageInfo = new PageInfo(datalist);

HashMap<String, Object> map= new HashMap<>();
       map.put("datalist", datalist);
       map.put("total", pageInfo.getTotal());
       map.put("size", pageInfo.getPageSize());
       map.put("page", pageInfo.getPageNum());

来源：https://blog.csdn.net/qq_41429436/article/details/121660890