How to insert the data in spreadsheet by using java
ListEntry row = new ListEntry();
row = spreadsheetService.insert(listFeedUrl, row);
Possible duplicate of: how to write the data in spreadsheet(reapated headers)
Have been looking through the documentation (old doc and new doc) and as far as I can tell, it has not been documented whether
setValueLocal(String header, String value) accepts a case-sensitive header value or not.
So, based on what you show, it appears that the specified header is not case-sensitive, meaning that the easiest way to fix this, is by renaming the headers in the spreadsheet giving them unique names.