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<String, Object> post(String url, JSONObject obj) {
Map<String, Object> resultMap = new HashMap<String, Object>();
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<String, Object> ret = post("http://localhost:8080/Try/calc", json);
System.out.println(ret);
}