Apache POI - the Java

public ArrayList<String> getXslxToArray(String fileName) {
ArrayList<String> rowList = new ArrayList<String>();
try {
org.apache.poi.xssf.usermodel.XSSFWorkbook xwb = new org.apache.poi.xssf.usermodel.XSSFWorkbook(new FileInputStream(new File(fileName)));
boolean isNull = false;
for (Row row : xwb.getSheetAt(0)) { //행구분
StringBuffer sb = new StringBuffer();
for (org.apache.poi.ss.usermodel.Cell cell : row) { //열구분
isNull = false;
switch (cell.getCellType()) {
case org.apache.poi.ss.usermodel.Cell.CELL_TYPE_STRING:
sb.append(cell.getRichStringCellValue().getString());
break;

case org.apache.poi.ss.usermodel.Cell.CELL_TYPE_NUMERIC:
if(DateUtil.isCellDateFormatted(cell)) {
sb.append(cell.getDateCellValue().toString());
} else {
sb.append(Integer.toString((int)cell.getNumericCellValue()));
}
break;

case org.apache.poi.ss.usermodel.Cell.CELL_TYPE_BOOLEAN:
sb.append(cell.getBooleanCellValue());
break;

case org.apache.poi.ss.usermodel.Cell.CELL_TYPE_FORMULA:
sb.append(cell.getCellFormula());
break;

case org.apache.poi.ss.usermodel.Cell.CELL_TYPE_BLANK:
sb.append("");
break;

default:
isNull = true;
break;
}
if(!isNull) {
sb.append("|");
}
}
rowList.add(sb.toString());
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return rowList;
}