code: public Excel03SaxReader read(POIFSFileSystem fs, int sheetIndex) throws POIException {
  		this.sheetIndex = sheetIndex;
  
  		formatListener = new FormatTrackingHSSFListener(new MissingRecordAwareHSSFListener(this));
  		final HSSFRequest request = new HSSFRequest();
  		if (isOutputFormulaValues) {
  			request.addListenerForAllRecords(formatListener);
  		} else {
  			workbookBuildingListener = new SheetRecordCollectingListener(formatListener);
  			request.addListenerForAllRecords(workbookBuildingListener);
  		}
  		final HSSFEventFactory factory = new HSSFEventFactory();
  		try {
  			factory.processWorkbookEvents(request, fs);
  		} catch (IOException e) {
  			throw new POIException(e);
  		}
  		return this;
  	}
docs: 读取
  
  @param fs {@link POIFSFileSystem}
  @param sheetIndex sheet序号
  @return this
  @throws POIException IO异常包装