public class FileDownLoadAction extends ActionSupport{

	private String filename;//下载文件的名称

	@Override

	public String execute() throws Exception {

		return SUCCESS;

	}

	//下载源

    public InputStream getInputStream() throws IOException{

    	String path =ServletActionContext.getServletContext().getRealPath(filename);//获取文件路径

    	//System.out.println("path="+path);

		File file = new File(path);

		return FileUtils.openInputStream(file);

	}

    //下载文件名

	public String getDownloadFileName() throws Exception{

		String downloadFileName="";

		String []filenames=filename.split("/");

		//System.out.println(filenames[filenames.length-1]);

		downloadFileName=URLEncoder.encode(filenames[filenames.length-1], "UTF-8");//解决下载中文命名文件乱码问题

	    return downloadFileName;

	}

	///////////////////////////////////////////字段封装//////////////

	public String getFilename() {

		return filename;

	}

	public void setFilename(String filename) {

		this.filename = filename;

	}

}

2、struts2.xml配置

<action name="download" class="com.zzuli.student.action.FileDownLoadAction">

		<!--以流的方式返回  -->

		<result name="success" type="stream">

		<!--文件流  -->

         <param name="contentType">application/octet-stream</param>

         <!--下载源  -->

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

         <!--以附件方式下载  downloadFileName相应Action类getDownloadFileName() -->

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

         <!--缓冲流大小  -->

         <param name="bufferSize">8192</param>

         </result>

3、jsp下载链接页面

<td>

<a href="download.action?filename=${documentUrl}">点击下载</a>

</td>