Created attachment 31625 [details]
A possible fix

Methods setFirstRow() setFirstColumn() setLastRow() setLastColumn() of class XSSFHyperlink do not work properly. In particular:
1) setFirstRow() setFirstColumn() throws NullPointerException
2) setLastRow() setLastColumn() overwrite first row and column instead of setting the other interval boundary.

E.g. the following code throws NullPointerException

XSSFCreationHelper creationHelper = myWorkbook.getCreationHelper();
XSSFHyperlink hyperlink = creationHelper.createHyperlink(Hyperlink.LINK_URL);
mySheet.addHyperlink(hyperlink);
hyperlink.setAddress("http://myurl");
hyperlink.setFirstRow(1);