struts实现的图片的上传和下载

 这是struts实现的图片的上传和下载的关键代码：

Java code

public class FileAction extends DispatchAction {    private JDBConnection connection =new JDBConnection();//以下方法实现文件的上传    public ActionForward upLoadFile(ActionMapping mapping, ActionForm form,                                    HttpServletRequest request,                                    HttpServletResponse response) throws            Exception {        Date date = new Date();        FileActionForm fileActionForm = (FileActionForm) form;        FormFile file = fileActionForm.getFile(); //获取当前的文件        String dir = servlet.getServletContext().getRealPath("/image");        String path = upload(dir, file); //实现文件的上传的功能,并且返回上传服务器的路径        path="image/"+path;        String fileName = Chinese.toChinese(fileActionForm.getFileName()); //获取文件的名称        String fileSize = String.valueOf(file.getFileSize());        String fileDate = DateFormat.getDateInstance().format(date);        String sql = "insert into tb_file values('" + fileName + "','" +                     fileSize + "','" + fileDate + "','" + path + "')";        connection.executeUpdate(sql);        connection.closeConnection();        return mapping.findForward("upLoadFileResult");    }    public String upload(String dir, FormFile formFile) throws Exception {         Date date = new Date();        //取欲上传的文件的名字和长度        String fname = formFile.getFileName();        //将上传时间加入文件名        int i = fname.indexOf(".");        String name = String.valueOf(date.getTime());        String type = fname.substring(i + 1);        fname = name + "." + type;        InputStream streamIn = formFile.getInputStream();    //创建读取用户上传文件的对象        File uploadFile = new File(dir);   //创建把上传数据写到目标文件的对象        if (!uploadFile.exists() || uploadFile == null) {  //判断指定路径是否存在，不存在则创建路径            uploadFile.mkdirs();        }        String path = uploadFile.getPath() + "/" + fname;        OutputStream streamOut = new FileOutputStream(path);        int bytesRead = 0;        byte[] buffer = new byte[8192];        while ((bytesRead = streamIn.read(buffer, 0, 8192)) != -1) {            streamOut.write(buffer, 0, bytesRead);        }        streamOut.close();        streamIn.close();        formFile.destroy();        return fname;    }    //实现文件的下载    public ActionForward downFile(ActionMapping mapping, ActionForm form,                                  HttpServletRequest request,                                  HttpServletResponse response) throws            Exception {        String path = request.getParameter("path");        BufferedInputStream bis = null;        BufferedOutputStream bos = null;        OutputStream fos = null;        InputStream fis = null;        String filepath = servlet.getServletContext().getRealPath("/" + path);        File uploadFile = new File(filepath);        fis = new FileInputStream(uploadFile);        bis = new BufferedInputStream(fis);        fos = response.getOutputStream();        bos = new BufferedOutputStream(fos);        response.setHeader("Content-disposition",                           "attachment;filename=" +                           URLEncoder.encode(path, "utf-8"));        int bytesRead = 0;        byte[] buffer = new byte[8192];        while ((bytesRead = bis.read(buffer, 0, 8192)) != -1) {            bos.write(buffer, 0, bytesRead);        }        bos.flush();        fis.close();        bis.close();        fos.close();        bos.close();        return null;    }}