The requirement was to parse an excel file which is in tabular format but number of columns, column names can be different for each excel, i.e. an unstructured excel file.
Since API activities like pxParseExcelFile , MSOParseExcel works with only excel files with a predefined structure, we needed a custom solution to fulfill our requirement. We have used Apache POI api to implement this.
Apache POI supports both XLS and XLSX type of files.