public Result listBkk(TargetSearchSubmit submit) {
        // 根据专题id筛选目标
        Result targetResult = getTargetBySubjectId(submit, false);
        if (targetResult != null) {
            return targetResult;
        }
        // 分页
        if (submit.getDoPage().equals(Boolean.TRUE)) {
            List<TargetBean> targetBeans = targetMapper.list(submit);
            // 专题信息和布控状态
            List<TargetBean> result = setSubjectAndbkStatus(targetBeans, true, submit.getBkStatus());
            PageInfo<TargetBean> pageInfo = new PageInfo<>(result);
            pageInfo.setList(startPage(result, submit.getPageNum(), submit.getPageSize()));
            return ResultGenerator.genSuccessResult(pageInfo);
        }
        // 不分页
        List<TargetBean> targetBeans = targetMapper.list(submit);
        // 专题信息和布控状态
        List<TargetBean> result = setSubjectAndbkStatus(targetBeans, true, submit.getBkStatus());
        return ResultGenerator.genSuccessResult(result);
    }

 /**
     * 开始分页
     *
     * @param list
     * @param pageNum  页码
     * @param pageSize 每页多少条数据
     * @return
     */
    public static List startPage(List list, Integer pageNum, Integer pageSize) {
        if (CollectionUtils.isEmpty(list)) {
            return Collections.emptyList();
        }

        // 记录总数
        Integer count = list.size();
        // 页数
        Integer pageCount;
        if (count % pageSize == 0) {
            pageCount = count / pageSize;
        } else {
            pageCount = count / pageSize + 1;
        }

        // 开始索引
        int fromIndex;
        // 结束索引
        int toIndex;
        if (!pageNum.equals(pageCount)) {
            fromIndex = (pageNum - 1) * pageSize;
            toIndex = fromIndex + pageSize;
        } else {
            fromIndex = (pageNum - 1) * pageSize;
            toIndex = count;
        }
        return list.subList(fromIndex, toIndex);
    }

原文链接：https://www.cnblogs.com/loong-hon/p/10863635.html