java using poi (XSSFWorkbook) read excel (.xlsx) files

After some searching found, the Java manipulate excel files commonly used in two ways jxl and poi , what good or bad to see their own needs.
The most important difference is that jxl does not support .xlsx, and poi support .xlsx
used here poi way of introduction (XSSFWorkbook), in fact poi provides HSSFWorkbook and XSSFWorkbook two implementation classes . The difference is that HSSFWorkbook against .xls file, XSSFWorkbook against .xslx file .
First, the basic concepts clear:
to create a workbook, a workbook can have multiple worksheets, a worksheet can have multiple rows, a row can have multiple cells in
a workbook --------- -> XSSFWorkbook
worksheet -----------> XSSFSheet
row -----------> XSSFRow
cell -----------> XSSFCell