How to know number of sheets in a workbook?

I'm using hssf api for reading data from xls files. But is there any way to get the exact no. of sheets in a workbook containing stored data?

How do I calculate total sheets in Excel?

Select a cell next to the numbers you want to sum, click AutoSum on the Home tab, press Enter, and you're done. When you click AutoSum, Excel automatically enters a formula (that uses the SUM function) to sum the numbers.

How do I count the number of tabs?

By performing a Find operation on the page ( ctrl / cmd + F) for the string inspect , Chrome will produce the Find input box containing the total number of instances of the searched string, and, in this case, the total number of open pages/tabs in your browser!

What does getNumberOfSheets return you?