1 <struts>
 2     <constant name="struts.multipart.maxSize" value="209715200" /><!-- 设置文件上传大小，2097152=2M -->
 3     <package name="action" extends="struts-default" namespace="/">
 4         <!-- 文件上传 -->
 5         <action name="upload" class="com.fileupload.action.UploadAction" method="execute">
 6             <result name="success">load_success.jsp</result><!-- 文件上传成功后跳转页面 -->
 7             <result name="message">/message.jsp</result><!-- 上传失败跳转页面 -->
 8             <interceptor-ref name="defaultStack">
 9                 <param name="fileUpload.allowedExtensions">jpg,png</param><!-- 设置上传格式 -->
10             </interceptor-ref>
11         </action>
12         <!-- 文件下载 -->
13         <action name="download" class="com.fileupload.action.DownloadAction" method="execute">
14             <result type="stream">
15                 <param name="inputName">is</param> <!-- 指定返回流的名字 -->
16                 <param name="contentType">application/pdf/jpg</param><!-- 指定返会数据的类型 -->
17                 <param name="contentDisposition">attachement;filename=${fileName}</param><!-- 指定用户下载的文件的类型和名称 -->
18             </result>
19         </action>
20     </package>
21 </struts>

 1 import java.io.File;
 2 import java.io.IOException;
 3 import org.apache.commons.io.FileUtils;
 4 import org.apache.struts2.ServletActionContext;
 5
 6 public class UploadAction {
 7     private File img; //文件
 8     private String imgFileName;  //文件名:文件+FileName
 9
10     public String execute() throws IOException{
11
12         if(img != null){
13         String path = ServletActionContext.getServletContext().getRealPath("/images");
14         File destFile = new File(path, imgFileName);
15         FileUtils.copyFile(img, destFile);
16         return "success";
17         }
18         return "message";
19     }
20
21     public File getImg() {
22         return img;
23     }
24     public void setImg(File img) {
25         this.img = img;
26     }
27     public String getImgFileName() {
28         return imgFileName;
29     }
30     public void setImgFileName(String imgFileName) {
31         this.imgFileName = imgFileName;
32     }
33 }

import java.io.FileNotFoundException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import org.apache.struts2.ServletActionContext;public class DownloadAction {private InputStream is;  //输入流，先将文件读入服务端的内存private String fileName; //随意    public String execute() throws FileNotFoundException, UnsupportedEncodingException{fileName = "1.png";//设置路径，在项目中通过连接DB获取文件名is = ServletActionContext.getServletContext().getResourceAsStream("/images/"+fileName);//获得文件流 　　　　byte[] bytes = fileName.getBytes("utf-8");　　  　fileName = new String(bytes, "iso-8859-1");

        return "success";}public InputStream getIs() {return is;}public void setIs(InputStream is) {this.is = is;}public String getFileName() {return fileName;}public void setFileName(String fileName) {this.fileName = fileName;}
}

File file = new File("D://spring.doc");
InputStream is = new FileInputStream(file);
return is; 

byte[] bytes = fileName.getBytes("utf-8");
fileName = new String(bytes, "iso-8859-1");