code: public CellStyle getOrCreateColumnStyle(int x) {
  		CellStyle columnStyle = this.sheet.getColumnStyle(x);
  		if (null == columnStyle) {
  			columnStyle = this.workbook.createCellStyle();
  			this.sheet.setDefaultColumnStyle(x, columnStyle);
  		}
  		return columnStyle;
  	}
docs: 获取或创建某一行的样式，返回样式后可以设置样式内容
  
  @param x X坐标，从0计数，既列号
  @return {@link CellStyle}
  @since 4.1.4