code: public static CellStyle createHeadCellStyle(Workbook workbook) {
  		final CellStyle cellStyle = workbook.createCellStyle();
  		setAlign(cellStyle, HorizontalAlignment.CENTER, VerticalAlignment.CENTER);
  		setBorder(cellStyle, BorderStyle.THIN, IndexedColors.BLACK);
  		setColor(cellStyle, IndexedColors.GREY_25_PERCENT, FillPatternType.SOLID_FOREGROUND);
  		return cellStyle;
  	}
docs: 创建默认头部样式
  
  @param workbook {@link Workbook} 工作簿
  @return {@link CellStyle}