public ExcelWriter setHeaderOrFooter(String text, Align align, boolean isFooter) {
		final HeaderFooter headerFooter = isFooter ? this.sheet.getFooter() : this.sheet.getHeader();
		switch (align) {
		case LEFT:
			headerFooter.setLeft(text);
			break;
		case RIGHT:
			headerFooter.setRight(text);
			break;
		case CENTER:
			headerFooter.setCenter(text);
			break;
		default:
			break;
		}
		return this;
	}
public ExcelWriter setHeaderOrFooter ( String text , Align align , boolean isFooter ) { final HeaderFooter headerFooter = isFooter ? this . sheet . getFooter ( ) : this . sheet . getHeader ( ) ; switch ( align ) { case LEFT : headerFooter . setLeft ( text ) ; break ; case RIGHT : headerFooter . setRight ( text ) ; break ; case CENTER : headerFooter . setCenter ( text ) ; break ; default : break ; } return this ; }
设置Excel页眉或页脚

@param text 页脚的文本
@param align 对齐方式枚举 {@link Align}
@param isFooter 是否为页脚，false表示页眉，true表示页脚
@return this
@since 4.1.0