java 实现逻辑分页

//逻辑分页
PageModel model = new PageModel();
long total = list.size();
model.setTotal(total);
model.setPageNum(pageNum);
model.setPageSize(pageSize);
long page= total % pageSize == 0 ? total / pageSize :  total/ pageSize + 1;
model.setTotalPage(page);
// 从第几条数据开始
long firstIndex;
long lastIndex;

if (pageNum > page){
    firstIndex = (page - 1) * pageSize;
    lastIndex = page * pageSize;
}else {
    firstIndex = (pageNum - 1) * pageSize;
    lastIndex = pageNum * pageSize;
}
if (list.size() < pageSize){
    model.setData(list);
}else if (page <= pageNum){
    model.setData(list.subList((int) firstIndex,(int)total));
} else {
    model.setData(list.subList((int) firstIndex,(int) lastIndex));
}

附：逻辑查询

int pageNum = externalIdList.size() % pageSize == 0 ? externalIdList.size() / pageSize : (externalIdList.size() / pageSize) + 1;

private static final int pageSize = 5000;
int start = i * pageSize;
int end = (i + 1) * pageSize > externalIdList.size() ? externalIdList.size() : (i + 1) * pageSize;
externalIdList.subList(start, end)