在Struts2中设置响应的内容类型

So, I'm using freemarker templates with Struts2 to formulate my responses. However, since I'm trying to use taconite as well, I need the response to be sent with the content type of "text/xml". I can't seem to find a way to use freemarker directives to set the content type, and I am not well versed enough in struts to know if there is a way to do it through that.So, I'm using freemarker templates with Struts2