java下載文件中文名稱亂碼(response.addHeader)

protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
         String browser = "";
         String fileName = "測試.txt";
            try {
                browser = request.getHeader("User-Agent");
                if (-1 < browser.indexOf("MSIE 6.0") || -1 < browser.indexOf("MSIE 7.0")) {
                    // IE6, IE7 瀏覽器
                    response.addHeader("content-disposition", "attachment;filename="
                            + new String(fileName.getBytes(), "ISO8859-1"));
                } else if (-1 < browser.indexOf("MSIE 8.0")) {
                    // IE8 
                    response.addHeader("content-disposition", "attachment;filename="
                            + URLEncoder.encode(fileName, "UTF-8"));
                } else if (-1 < browser.indexOf("MSIE 9.0")) {
                    // IE9
                    response.addHeader("content-disposition", "attachment;filename="
                            + URLEncoder.encode(fileName, "UTF-8"));
                } else if (-1 < browser.indexOf("Chrome")) {
                    // 谷歌
                    response.addHeader("content-disposition",
                            "attachment;filename*=UTF-8''" + URLEncoder.encode(fileName, "UTF-8"));
                } else if (-1 < browser.indexOf("Safari")) {
                    // 蘋果
                    response.addHeader("content-disposition", "attachment;filename="
                            + new String(fileName.getBytes(), "ISO8859-1"));
                } else {
                    // 火狐或者其他的瀏覽器
                    response.addHeader("content-disposition",
                            "attachment;filename*=UTF-8''" + URLEncoder.encode(fileName, "UTF-8"));
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            InputStream in = new FileInputStream("D:\\test.txt");//獲取文件輸入流
             int len = 0;
             byte[] buffer = new byte[1024];
             OutputStream out = response.getOutputStream();
             while ((len = in.read(buffer)) > 0) {
                 out.write(buffer,0,len);//將緩沖區的數據輸出到客戶端瀏覽器
             }
             in.close();
             out.flush();
             out.close();
    }

 判斷各個瀏覽器,然后進行解碼和加碼