import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public static void main (String [] argv) throws Exception {
InputStream in = new ByteArrayInputStream(data);
Workbook wb = new XSSFWorkbook(in);
in.close();
Sheet sheet1 = wb.getSheet("Sheet1");
Row row = sheet1.getRow(0);
Cell a1 = row.getCell(0);
System.out.println(a1.getStringCellValue());
}