code: public static ExcelReader getReader(File bookFile, String sheetName) {
  		try {
  			return new ExcelReader(bookFile, sheetName);
  		} catch (NoClassDefFoundError e) {
  			throw new DependencyException(ObjectUtil.defaultIfNull(e.getCause(), e), PoiChecker.NO_POI_ERROR_MSG);
  		}
  	}
docs: 获取Excel读取器，通过调用{@link ExcelReader}的read或readXXX方法读取Excel内容
  
  @param bookFile Excel文件
  @param sheetName sheet名，第一个默认是sheet1
  @return {@link ExcelReader}