```java
PageHelper pageHelper = new PageHelper();
PageHelper.startPage(1,10);
// returnData 是我的所有数据 可这样分页会失败 无法分页
PageInfo<Map<String, Object>> mapPageInfo = new PageInfo<>(returnData);
```xml
pageNum = 1
pageSize = 12
size = 12
startRow = 0
endRow = 11
pages = 1
prePage = 0
nextPage = 0
isFirstPage = true
isLastPage = true
hasPreviousPage = false
hasNextPage = false
navigatePages = 8
navigatepageNums = {int[1]@14926}
navigateFirstPage = 1
navigateLastPage = 1
total = 12