java 在 Struts2 中设置响应的内容类型

Setting the content-type of a response in Struts2

提问by Thomas

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.

所以，我在 Struts2 中使用 freemarker 模板来制定我的回复。但是，由于我也尝试使用 taconite，因此我需要以“text/xml”的内容类型发送响应。我似乎无法找到一种使用 freemarker 指令来设置内容类型的方法，而且我对 struts 不够精通，不知道是否有办法做到这一点。

So, how should I go about this?

那么，我应该怎么做呢？

回答by Lastnico

In your Action class, implements the ServletResponseAwareinterface, and use a simple:

在你的 Action 类中，实现ServletResponseAware接口，并使用一个简单的：

package your.package;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.opensymphony.xwork2.ActionSupport;
import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.interceptor.ServletResponseAware;

public class YourAction extends ActionSupport implements 
                 ServletResponseAware {

  private HttpServletResponse response;

  public String execute() throws Exception{
    response.setContentType("image/png");
    return SUCCESS;
  }

  public void setServletResponse(HttpServletResponse response){
    this.response = response;
  }

  public HttpServletResponse getServletResponse(){
    return response;
  }
}

More information here:http://www.roseindia.net/struts/struts2/strutsresources/access-request-response.shtml

更多信息在这里：http: //www.roseindia.net/struts/struts2/strutsresources/access-request-response.shtml

回答by Ulf Lindback

Or you can set it in the struts.xml

或者你可以在struts.xml中设置

<action name="..." class="...">
  <result name="SUCCESS">
    <param name="contentType">text/html</param>

回答by Rodney Gitzel

Implementing ServletResponseAwaremight work in other situations, but it doesn't help with Freemarker and Struts2. :-( I just traced it through with a debugger, and found that...

ServletResponseAware在其他情况下实施可能有效，但对 Freemarker 和 Struts2 没有帮助。:-(我只是用调试器跟踪它，发现......

• by implementing ServletResponseAware, I was given access to the response, and I could change the content-type from my action. Good.

• once my action was done, control soon ended up in org.apache.struts2.views.freemarker.FreemarkerResult, which renders the template

• the method preTemplateProcess()sets the response's content-type, ignoring the value I had set :-(

• apparently there's a "custom attribute" that could be used to override this, but I haven't found any explanation in google yet

• the FreemarkerResultclass itself can have a content-type set to override the default, but... not sure yet where that can be set from, maybe in a struts configuration?

• 通过实现ServletResponseAware，我可以访问响应，并且可以从我的操作中更改内容类型。好的。

• 一旦我的动作完成，控制很快就会结束org.apache.struts2.views.freemarker.FreemarkerResult，这会呈现模板

• 该方法preTemplateProcess()设置响应的内容类型，忽略我设置的值:-(

• 显然有一个“自定义属性”可以用来覆盖它，但我还没有在谷歌中找到任何解释

• 在FreemarkerResult类本身可以拥有的内容类型设置为覆盖默认的，但是...还不确定，其中，可以从设定，也许在一个Struts配置？

So so far it doesn't seem that the action can set the content-type, but fortunately as Thomas notes above, this overrides all that:

到目前为止，该操作似乎无法设置内容类型，但幸运的是，正如 Thomas 上面提到的，这覆盖了所有内容：

${response.setContentType("text/xml")}

${response.setContentType("text/xml")}

So at least it's possible from the templates. Sure would be easier and safer to give a set of xml-producing actions a common superclass that takes care of this...

所以至少从模板中是可能的。当然，为一组 xml 生成操作提供一个通用的超类来处理这个问题会更容易和更安全......

回答by jsalvata

Or, if you prefer annotations:

或者，如果您更喜欢注释：

@Result(name=SUCCESS, location="...", params={"contentType", "text/html"})

回答by Thomas

Answered my own question:

回答了我自己的问题：

Use the following code at the type of the template:

在模板类型处使用以下代码：

${response.setContentType("text/xml")}