[JAVA] Http POST urlencoded

public int postRequset(Map<String, Object> paramMap) throws IOException {

        @Cleanup CloseableHttpClient client = HttpClientBuilder.create().build();

        Map<String, Object> requestMap = new HashMap<>();
        requestMap.put("type"             , type);     //파라메터

        HttpPost post = new HttpPost("url");
        post.setHeader("Content-Type", "application/x-www-form-urlencoded;charset=utf-8");
        List<NameValuePair> paramList = convertParam(requestMap);

        post.setEntity(new UrlEncodedFormEntity(paramList, "UTF-8"));
        ResponseHandler<String> rh = new BasicResponseHandler();

        String returnStr = client.execute(post, rh);

       return 0;
    }

private static List<NameValuePair> convertParam(Map<String, Object> params) {
        List<NameValuePair> paramList = new ArrayList<NameValuePair>();

        if(params != null) {
            for(Object item : params.keySet()) {
                String key = String.valueOf(item);
                paramList.add(new BasicNameValuePair(key, params.get(key).toString()));
            }
        }

        return paramList;
    }