1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <%@taglib uri="/struts-tags" prefix="s"%>
 4 <!DOCTYPE html>
 5 <html>
 6     <head>
 7         <meta charset="UTF-8">
 8         <title>struts2的一个例子</title>
 9     </head>
10     <body>
11         <s:form action="downloadFile.action" method="post" enctype="multipart/form-data">
12             <s:submit value="下载文件"/>
13         </s:form>
14         
15     </body>
16 </html>
index.jsp代码 
 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE struts PUBLIC
 3     "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
 4     "http://struts.apache.org/dtds/struts-2.3.dtd">
 5 <struts>
 6     <constant name="struts.devMode" value="true"/>
 7     <package name="hello" extends="struts-default" namespace="/">
 8         <action name="downloadFile" class="com.xiaostudy.web.DownloadFile" method="downloadFile">
 9             <result name="success" type="stream">
10                 <param name="inputName">fileInputStream</param>
11                 <param name="contentDisposition">attachment;filename=image.jpg</param>
12                 <param name="contentType">application/octet-stream</param>
13             </result>
14         </action>
15     </package>
16 </struts>
struts.xml代码 
 1 package com.xiaostudy.web;
 2 
 3 import java.io.File;
 4 import java.io.FileInputStream;
 5 import java.io.FileNotFoundException;
 6 import java.io.InputStream;
 7 
 8 import org.apache.struts2.ServletActionContext;
 9 
10 import com.opensymphony.xwork2.ActionSupport;
11 
12 public class DownloadFile extends ActionSupport {
13     
14     public InputStream fileInputStream;
15     public String downloadFile() throws FileNotFoundException {
16         
17         String path = ServletActionContext.getServletContext().getRealPath("/WEB-INF/files/CSS.jpg");
18         fileInputStream = new FileInputStream(new File(path));
19         
20         return SUCCESS;
21     }
22     public InputStream getFileInputStream() {
23         return fileInputStream;
24     }
25     public void setFileInputStream(InputStream fileInputStream) {
26         this.fileInputStream = fileInputStream;
27     }
28 
29 
30 }
action动作类DownloadFile