spring json接口开发及调用

@RequestMapping(value = "calc" , produces="text/html;charset=UTF-8")
	@ResponseBody
	public String calc(
			@RequestBody JSONObject jsonObj){
		Long numA = jsonObj.getLong("numA") ;
		Long numB = jsonObj.getLong("numB") ;
		
		JSONObject json = new JSONObject() ;
		json.put("retCode", "001") ;
		json.put("res" , numA + numB) ;
		
		return json.toJSONString()  ;
	}

public static Map post(String url, JSONObject obj) {
		Map resultMap = new HashMap();
		HttpPost post = new HttpPost(url);
		post.addHeader(HTTP.CONTENT_TYPE, "application/json;charset=UTF-8");
		StringEntity se = new StringEntity(obj.toJSONString(), "UTF-8");
		se.setContentType("text/json;charset=UTF-8");
		se.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE,
				"application/json;charset=UTF-8"));
		post.setEntity(se);
		HttpResponse response = null;
		try {
			response = new DefaultHttpClient().execute(post);
			if (response != null && response.getEntity() != null) {
				String out = EntityUtils.toString(response.getEntity());
				resultMap = JSONObject.parseObject(out, Map.class);
			} else {
				resultMap.put("rtnMsg", "失败!");
			}
		} catch (Exception e) {
			resultMap.put("rtnMsg", "失败!");
		} finally {
		}

		return resultMap;
	}

public static void main(String[] args) {
		JSONObject json = new JSONObject();
		json.put("numA", 11);
		json.put("numB", 22);
		Map ret = post("http://localhost:8080/Try/calc", json);
		System.out.println(ret);
	}