struts2

Posted 2020-07-26 韩说不白说

1:Stream

 <result-type name="stream" class="org.apache.struts2.result.StreamResult"/>

 

A custom Result type for sending raw data (via an InputStream) directly to the HttpServletResponse. Very useful for allowing users to download content.

This result type takes the following parameters: 

• contentType - the stream mime-type as sent to the web browser (default = text/plain).
• contentLength - the stream length in bytes (the browser displays a progress bar).
• contentDisposition - the content disposition header value for specifing the file name (default = inline, values are typically attachment;filename="document.pdf".
• inputName - the name of the InputStream property from the chained action (default = inputStream).

 

 

 

 

步1：开发一个action，提供一个getInputStream():InputStream

 

public class DownAction extends ActionSupport {

@Override

public String execute() throws Exception {

System.err.println("判断用户的积分，判断用户的状态..");

return SUCCESS;

}

 

public InputStream getInputStream() throws Exception {

String path = ServletActionContext.getServletContext().getRealPath("/files/yy.zip");

InputStream in = new FileInputStream(path);

return in;

}

}

 

步2：配置到stuts.xml中且返回的<result type=”stream”/>

<action name="down" class="cn.down.DownAction">

<result type="stream"></result>

</action>

 

<action name="down" class="cn.down.DownAction">

<result type="stream">

<param name="contentType">application/force-download</param>

<param name="contentDisposition">attachment;filename="document.zip"</param>

</result>

</action>

 

 

 

 

附加：

 1：下载时修改名称

String name = "我的文件.zip";

name = URLEncoder.encode(name,"UTF-8");

ActionContext.getContext().put("fileName", name);

在XML中取值：

   在XML中使用OGNL取值，是通过${..}

 

 

<action name="down" class="cn.struts2.down.DownAction">

<result type="stream">

<param name="contentType">application/force-download</param>

<param name="contentDisposition">attachment;filename="${fileName}"</param>

</result>

</action>

 

 

 

 

--通过inputName指定方法名：

<action name="down" class="cn.struts2.down.DownAction">

<result type="stream">

<param name="contentType">application/force-download</param>

<param name="contentDisposition">attachment;filename="${fileName}"</param>

<!-- 在DownAction.getDownfile():InputStream -->

<param name="inputName">downfile</param>

</result>

</action>

 

public InputStream getDownfile() throws Exception {

String path = ServletActionContext.getServletContext().getRealPath("/files/yy.zip");

InputStream in = new FileInputStream(path);

return in;

}