List<ExcelData> dataList = Lists.newArrayList();
bis = new BufferedInputStream(is);
OPCPackage pkg = OPCPackage.open(bis);
XSSFReader r = new XSSFReader(pkg);
XMLReader parser =
XMLReaderFactory.createXMLReader();
ContentHandler handler = new Excel2007ImportSheetHandler(proxy, dataList, batchSize);
parser.setContentHandler(handler);
Iterator<InputStream> sheets = r.getSheetsData();
while (sheets.hasNext()) {
InputStream sheet = null;
try {
sheet = sheets.next();
InputSource sheetSource = new InputSource(sheet);