Project scenario:
Use PageHelper pagination query, return data error
Problem Description
The total number detected is always equal to the number displayed on each page, not the actual number of data
参数：pageNumber=1 pageSize=2，数据库实际数量20
{
"page": {
"total": 2,
"list": ["1","2"],
"pageNum": 1,
"pageSize": 2,
"size": 7,
"startRow": 1,
"endRow": 7,
"pages": 1,
"prePage": 0,
"nextPage": 0,
"isFirstPage": true,
"isLastPage": true,
"hasPreviousPage": false,
"hasNextPage": false,
"navigatePages": 8,
"navigatepageNums": [
1
],
"navigateFirstPage": 1,
"navigateLastPage": 1
}
}
Cause Analysis:
List<XxxxVO> xxxxVOS = BeanHelper.copyCollection(list, XxxxVO .class); new PageInfo<>(xxxxVOS);//The problem lies here //Note: BeanHelper here is a custom type conversion class
After using pagination, after performing type conversion on the queried data, and then assigning it to PageInfo, the total number of data will change to the value of the current collection instead of the total value of the database.
solution:
List<XxxxEntity> list = queryList(dto); PageInfo pageInfo = new PageInfo<>(list);//Assign value first, be careful not to write specific generics List<XxxxVO> xxxxVOS = BeanHelper.copyCollection(list, XxxxVO .class); pageInfo.setList( xxxxVOS );//Put the transformed collection into it
First put the queried list collection into PageInfo, be careful not to specify data generics here , and then put the converted collection into it after type conversion
{
"page": {
"total": 20,
"list": ["1","2"],
"pageNum": 1,
"pageSize": 2,
"size": 7,
"startRow": 1,
"endRow": 7,
"pages": 1,
"prePage": 0,
"nextPage": 0,
"isFirstPage": true,
"isLastPage": true,
"hasPreviousPage": false,
"hasNextPage": false,
"navigatePages": 8,
"navigatepageNums": [
1
],
"navigateFirstPage": 1,
"navigateLastPage": 1
}
}