public void downloadFile() {
        try {

            HttpServletResponse response = ServletActionContext.getResponse();
            HttpServletRequest request = ServletActionContext.getRequest();

            String webHost = request.getContextPath();
            handbookUrl = new String(handbookUrl.getBytes("ISO-8859-1"), "UTF-8");

            String filePath = handbookUrl;
            filePath = request.getRealPath(filePath);

            download(filePath, response);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public HttpServletResponse download(String path, HttpServletResponse response) {
        try {
            // path是指欲下载的文件的路径。
            File file = new File(path);
            // 取得文件名。
            String filename = file.getName();

            // 以流的形式下载文件。
            InputStream fis = new BufferedInputStream(new FileInputStream(path));

            // 清空response
            response.reset();
            // 设置response的Header

            response.setBufferSize(5 * 1024 * 1024);

            filename = new String(filename.getBytes("GBK"), "ISO8859_1");

            response.addHeader("Content-Disposition", "attachment;filename=" + filename);
            response.addHeader("Content-Length", "" + file.length());
            OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/octet-stream");

            int readLength = 0;
            byte[] readUnit = new byte[1024 * 1024];
            while ((readLength = fis.read(readUnit)) != -1) {
                toClient.write(readUnit, 0, readLength);
                toClient.flush();
            }
            fis.close();
            toClient.flush();
            toClient.close();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
        return response;
    }

------解决方案--------------------
http://www.vaannila.com/struts-2/struts-2-example/struts-2-file-Upload-example-1.html

You can download the Struts 2 File Upolad example by clicking the Download link below.
Source :Download
War :Download

------解决方案--------------------

上传
Java code
/*
     * 上传文件
     */
    public String uploadFile(File upload, String uploadFileName,
            String directory) {
        String path = "upload";

        String filePath = "";
        try {

            HttpServletRequest request = ServletActionContext.getRequest();

            String fileName = uploadFileName;

            // 获取物理路径
            String sPath = request.getRealPath(path+File.separator + directory)+File.separator;
            // 获取网络地址
            filePath = path + "/" + directory
                    + "/" + fileName;

            String outputFileName = sPath + fileName;

            File outputPathFile = new File(sPath);
            if (!outputPathFile.exists()) {
                outputPathFile.mkdirs();
            }

            // 保存文件
            File outputFile = new File(outputFileName);
            java.io.InputStream is = new FileInputStream(upload);
            java.io.OutputStream os = new java.io.FileOutputStream(outputFile);

            if (outputFile.exists())
                outputFile.delete();