java请求POST发送json格式请求

 public static String upload(String url){
        try {
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost(url);
            MultipartEntity reqEntity = new MultipartEntity();
            ArrayList<HashMap<String,String>> enclosureList = new ArrayList<HashMap<String, String>>();
            for (int i = 0; i <10 ; i++) {
                HashMap<String,String> tmpHash = new HashMap<String, String>();
                tmpHash.put("name","testfile"+i+".jpg");
                tmpHash.put("url","CgAE3FdNSROAVQqrAAD8dT1kf6k929"+i+".jpg");
                enclosureList.add(tmpHash);
            }

            JSONArray enclosure = JSONArray.fromObject(enclosureList);
            StringBody enclosure_str = new StringBody(enclosure.toString());
            //json格式的请求数据封装　　　　　　　JSONObject param = new JSONObject();
            param.put("bidId","1027228");
            param.put("datumId","102");
            param.put("enclosure",enclosure.toString());
            System.out.println(param.toString());
            StringEntity se = new StringEntity(param.toString());
            httppost.setEntity(se);
            HttpResponse response = httpclient.execute(httppost);
            int statusCode = response.getStatusLine().getStatusCode();
            if(statusCode == HttpStatus.SC_OK){
                System.out.println("服务器正常响应.....");
                HttpEntity resEntity = response.getEntity();
　　　　　　　　　　//解析json格式的返回结果                JSONObject json = JSONObject.fromObject(EntityUtils.toString(resEntity).toString());
                System.out.println(json.toString());
                EntityUtils.consume(resEntity);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }