怎么在java中利用HttpClient PostMethod对json数据进行提交

HttpClient httpClient = new HttpClient();
 String host = (String) BaseConfig.get("host");
 String port = (String) BaseConfig.get("port");
 httpClient.getHostConfiguration().setProxy(host, Integer.valueOf(port));
 PostMethod postMethod = new PostMethod(applyurl);
 JSONObject jsonObject = new JSONObject();
 jsonObject.put("name",user.getName());
 jsonObject.put("phone",user.getPhone());
 jsonObject.put("provinceCode",user.getProvinceCode()); 
 jsonObject.put("cityCode",user.getCityCode()); 
 jsonObject.put("buyModelCode",user.getBuyModelCode()); 
 jsonObject.put("dealerCode",user.getDealerCode()); 
 jsonObject.put("url","http:xxx"); 
 String toJson = jsonObject.toString();
 RequestEntity se = new StringRequestEntity (toJson ,"application/json" ,"UTF-8");
 postMethod.setRequestEntity(se);
 postMethod.setRequestHeader("Content-Type","application/json");
 //默认的重试策略
 postMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, new DefaultHttpMethodRetryHandler());
 postMethod.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, 5000);//设置超时时间
 int httpStatus = hc.executeMethod(postMethod);
 String str=postMethod.getResponseBodyAsString();
 T.console("str-------:"+str);

//HttpClient发起请求
public static String sendUrlFile(String url, String jsonstr) { 
 String result = "";
 try { 
 HttpClient httpclient = new HttpClient();
 PostMethod post = new PostMethod(url); 
 FilePart filePart = new FilePart("file", new File("/root/桌面/文档/记录.txt"));
 filePart.setCharSet("utf-8"); 
 post.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET, "utf-8");
 //Part数组装需要传第的参数和文件等
 Part[] parts = {new StringPart("username",jsonstr , "utf-8"),filePart};
 MultipartRequestEntity entity = new MultipartRequestEntity(parts, post.getParams());
 post.setRequestEntity(entity);
 int code = httpclient.executeMethod(post);
 //拿到响应结果
 result = new String(post.getResponseBody(), "UTF-8");
 //可释放连接
 post.releaseConnection(); 
 return result;
 } catch (HttpException h) {
 LOGGER.error("cause HttpException:" + h.getMessage()); 
 } catch (Exception i) {
 LOGGER.error("发送请求错误： url cause IOException:" + i.getMessage());
 } 
 return "";
}
//接收请求服务器端 参数需要和发送端一致

@ResponseBody
@RequestMapping(value = “/login”)
public JsonResult revice(@RequestParam(“file”) MultipartFile file,@RequestParam(“username”)String username) throws IOException{
InputStream in = file.getInputStream();
OutputStream out = new FileOutputStream("/root/桌面/ok.txt");
byte[] bs = new byte[1024];
int len;
while(-1 != (len = (in.read(bs)))){
out.write(bs);
}
JsonResult json = new JsonResult();
System.out.println();
json.setResult(“ok”);
return json;
}