图片上传到指定服务器(后台)

前台实现:需要引入jquery.form.js

$("#file1").change(function(){
    $("#form1").ajaxSubmit(function(data){ 
        $("#testImg1").attr("src",data.data.picUrl+data.data.imgfurl);
    }); 
});

/**
     * 手持上传
     * @param file
     * @param request
     * @return
     * @throws Exception
     */
    @RequestMapping("/uploadImgsc")
    @ResponseBody
    public ResultMap uploadImgsc(@RequestParam(value = "uploadFile", required = false) MultipartFile file
            ,HttpServletRequest request) throws Exception{
//    String imgUrl = Constant.imageUrl+"/fastupload_w/fast/upload";
        System.out.println("file:"+file);
        String imgUrl = "http://image.xxxx.com/fastupload_w/fast/upload" +
                "";
        String imgfurl = "";
        int maxSize = 5 * 1024 * 1024; // 5M
// 获得文件类型（可以判断如果不是图片，禁止上传）
        File dest = uploadFileDest(file, request);
//将内存中的文件写入磁盘
        file.transferTo(dest);
        imgfurl = Upload.uploadFile(dest, imgUrl);
        if (imgfurl==null){
            return ResultMap.error("上传失败");
        }
        JSONObject img=JSONObject.parseObject(imgfurl);
        dest.delete();
        logger.info("上传路径:"+imgfurl);
        JSONObject param=new JSONObject();
        param.put("imgfurl",img.get("url"));
        param.put("picUrl","http://read.image.39tx.cc/" +
                "");
        System.out.println("上传完毕");
        return ResultMap.ok(param);
    }



    private File uploadFileDest(MultipartFile file, HttpServletRequest request) {
//获取容器 再获取项目根目录 
        String pathRoot = request.getSession().getServletContext().getRealPath("/");
//网页中存在的Content-Type类型
        String contentType = file.getContentType();
        System.out.println("contentType:"+contentType);
        String uuid = UUID.randomUUID().toString().replaceAll("-", "");
//获取文件后缀名称 如:image/png
        String imageName = contentType.substring(contentType.indexOf("/") + 1);
        String path = "upload/" + uuid + "." + imageName;
        logger.info("存放本地路径:"+pathRoot + path);
        File dest = new File(pathRoot + path);

        if(!dest.exists()){
//获取父目录,在生成文件
            dest.getParentFile().mkdirs();
        }
        return dest;
    }



    /**
     * 上传文件到服务器
     *
     * @param file
     * 需要上传的文件
     * @param RequestURL
     * 请求的rul <a href='\"http://cccc.jpg\"'
     * target='\"_blank\"'>@return</a> 返回响应的内容
     */

    public static String uploadFile(File file, String RequestURL)

    {

        String result = null;
        String BOUNDARY = UUID.randomUUID().toString(); // 边界标识 随机生成
        String PREFIX = "--", LINE_END = "\r\n";
        String CONTENT_TYPE = "multipart/form-data"; // 内容类型

        try {
            URL url = new URL(RequestURL);

            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setReadTimeout(TIME_OUT);
            conn.setConnectTimeout(TIME_OUT);
            conn.setDoInput(true); // 允许输入流
            conn.setDoOutput(true); // 允许输出流
            conn.setUseCaches(false); // 不允许使用缓存
            conn.setRequestMethod("POST"); // 请求方式
            conn.setRequestProperty("Charset", CHARSET); // 设置编码
            conn.setRequestProperty("connection", "keep-alive");
            conn.setRequestProperty("Content-Type", CONTENT_TYPE + ";boundary="
                    + BOUNDARY);

            if (file != null)
            {
/**
 * 当文件不为空，把文件包装并且上传
 */

                DataOutputStream dos = new DataOutputStream(
                        conn.getOutputStream());

                StringBuffer sb = new StringBuffer();
                sb.append(PREFIX);
                sb.append(BOUNDARY);
                sb.append(LINE_END);

/**
 * 这里重点注意： name里面的值为服务器端需要key 只有这个key 才可以得到对应的文件
 * filename是文件的名字，包含后缀名的 比如:abc.png
 */
                sb.append("Content-Disposition: form-data; name=\"desc\"" + ""
                        + "\n" + LINE_END + "zt" + LINE_END);
                sb.append(PREFIX);
                sb.append(BOUNDARY);
                sb.append(LINE_END);
                sb.append("Content-Disposition: form-data; name=\"photo\"; filename=\""
                        + file.getName() + "\"" + LINE_END);
                sb.append("Content-Type: image/*; charset=" + CHARSET
                        + LINE_END);

                sb.append(LINE_END);
                dos.write(sb.toString().getBytes());
                InputStream is = new FileInputStream(file);
                byte[] bytes = new byte[1024];
                int len = 0;

                while ((len = is.read(bytes)) != -1)

                {
                    dos.write(bytes, 0, len);
                }
                is.close();
                dos.write(LINE_END.getBytes());

                byte[] end_data = (PREFIX + BOUNDARY + PREFIX + LINE_END)
                        .getBytes();

                dos.write(end_data);
                dos.flush();
/**
 * 获取响应码 200=成功 当响应成功，获取响应的流
 */
                int res = conn.getResponseCode();
                System.out.println("response code:" + res);

// if(res==200)

// {

                System.out.println("request success");

                InputStream input = conn.getInputStream();
                StringBuffer sb1 = new StringBuffer();

                int ss;
                while ((ss = input.read()) != -1) {
                    sb1.append((char) ss);

                }
                result = sb1.toString();
                System.out.println("result : " + result);
// }
// else{
// Log.e(TAG, "request error");
// }
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return result;
    }