Some questions about cell data types and how they work:
How does Aspose.Cells determine the data type of a cell in a spreadsheet?
Does the INT type have any meaning?
Can you set a cell so that it has a particular value type?
Does the cell type change if you apply formatting (for example format a double as a date?)
PS you've a minor documentation bug in the java api docs - Interface CellValueType DOUBLE is listed as DOULE