PoiTest

public class PoiTest {

static public void main(String[] args) throws Exception {

 FileOutputStream fos = new FileOutputStream("d://foo.xls");
 HSSFWorkbook wb = new HSSFWorkbook();
 HSSFSheet s = wb.createSheet();
 wb.setSheetName(0, "Matrix");
 for(short i=0; i<50; i++) {
  HSSFRow row = s.createRow(i);
  for(short j=0; j<50; j++) {
   HSSFCell cell = row.createCell(j);
   cell.setCellValue(""+i+","+j);
  }
 }
 wb.write(fos);
 fos.close();
}
}