java文件下载，并修改文件名，解决中文乱码

public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, java.io.IOException {
			String saveUrl = request.getParameter("url");
			
			//有配置存储路径
			String savePath = ConfUtil.getValue("savePath");
			if(savePath != null && !"".equals(savePath)) {
				saveUrl = savePath + "/" + saveUrl;
			}else{
			//无存储路径时，读默认的存储位置，sc项目下
				saveUrl = request.getSession().getServletContext()
						.getRealPath("") + saveUrl;
			}
	        File f = new File(saveUrl);
	        if (!f.exists()) {
	            response.sendError(404, "File not found!");
	            return;
	        }
	        BufferedInputStream br = new BufferedInputStream(new FileInputStream(f));
	        byte[] buf = new byte[1024];
	        int len = 0;

	        String fn = request.getParameter("fn");
			if(fn == null || fn.isEmpty()){
				fn = f.getName();
			}
			
	        System.out.println(f.getName()+"============");
	        
	        response.reset(); // 非常重要
	        // 纯下载方式
            response.setContentType("application/x-msdownload");
            System.out.println(f.getName());
            System.out.println(fn);
            String formatFileName = encodingFileName(fn);
//	        response.setHeader("Content-Disposition", "attachment; filename=" + f.getName());
	        response.setHeader("Content-Disposition", "attachment; filename=" + formatFileName);
	        
	        OutputStream out = response.getOutputStream();
	        while ((len = br.read(buf)) > 0)
	            out.write(buf, 0, len);
	        br.close();
	        out.close();
		
		}
	
	public static String encodingFileName(String fileName) {
        String returnFileName = "";
        try {
            returnFileName = URLEncoder.encode(fileName, "UTF-8");
            returnFileName = StringUtils.replace(returnFileName, "+", "%20");
            if (returnFileName.length() > 150) {
                returnFileName = new String(fileName.getBytes("GB2312"), "ISO8859-1");
                returnFileName = StringUtils.replace(returnFileName, " ", "%20");
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
            if (log.isWarnEnabled()) {
                log.info("Don't support this encoding ...");
            }
        }
        return returnFileName;
    }