/**
     * 上传文件
     * 
     * @param uploadUrl
     *            上传地址
     * @param param
     *            参数
     * @param filepath
     *            文件路径
     * @return 结果
     */
    public static String upload(String uploadUrl, HashMap<String, String> param, String fieldName, String filepath) {
        StringBuilder result = null;
        try {
            String boundary = "---------------------------esa000000000001";
            URL url = new URL(uploadUrl);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoOutput(true);
            connection.setDoInput(true);
            connection.setUseCaches(false);
            connection.setConnectTimeout(1000 * 20);
            connection.setReadTimeout(1000 * 20);
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Connection", "Keep-Alive");
            connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
            connection.setRequestProperty("Charsert", "UTF-8");

            File file = new File(filepath);
            StringBuilder sbf = new StringBuilder();
            sbf.append("--" + boundary + "\r\n");
            sbf.append("Content-Disposition: form-data; name=\"" + fieldName + "\"; filename=\"" + file.getName() + "\"\r\n");
            sbf.append("Content-Type: application/octet-stream" + "\r\n\r\n");
            byte[] fz = sbf.toString().getBytes();
            StringBuilder sb = new StringBuilder();
            sb.append("\r\n\r\n");
            Iterator<String> iterator = param.keySet().iterator();
            while (iterator.hasNext()) {
                String key = iterator.next();
                String value = param.get(key);
                sb.append("--" + boundary + "\r\n");
                sb.append("Content-Disposition: form-data; name=\"" + key + "\"\r\n");
                sb.append("\r\n");
                sb.append(value + "\r\n");
            }
            byte[] before = sb.toString().getBytes();
            byte[] after = ("\r\n--" + boundary + "--\r\n").getBytes();
            connection.setRequestProperty("content-length", (before.length + fz.length + file.length() + after.length) + "");
            DataOutputStream dos = new DataOutputStream(connection.getOutputStream());
            dos.write(fz);
            FileInputStream fis = new FileInputStream(file);
            byte[] buffer = new byte[1024 * 10];
            int len;
            while ((len = fis.read(buffer)) != -1) {
                dos.write(buffer, 0, len);
            }
            dos.write(before);
            dos.write(after);
            dos.flush();
            int code = connection.getResponseCode();
            InputStream stream = connection.getInputStream();
            byte[] b = new byte[1024 * 10];
            int l;
            result = new StringBuilder();
            while ((l = stream.read(b)) != -1) {
                result.append(new String(b, 0, l, "utf-8"));
            }
            fis.close();
            dos.close();
            stream.close();
        } catch (MalformedURLException e) {
        } catch (ProtocolException e) {
        } catch (IOException e) {
        } finally {

        }
        if (result == null) {
            return null;
        } else {
            return result.toString();
        }
    }