JSON数据之间的转换

1. //把java 对象列表转换为json对象数组，并转为字符串

    JSONArray array = JSONArray.fromObject(userlist);
    String jsonstr = array.toString();

2.//把java对象转换成json对象，并转化为字符串

  JSONObject object = JSONObject.fromObject(invite);
  Log4jInit.ysulogger.debug(object.toString());

3.//把JSON字符串转换为JAVA 对象数组

  String personstr = getRequest().getParameter("persons");
  JSONArray json = JSONArray.fromObject(personstr);
  List<InvoidPerson> persons = (List<InvoidPerson>)JSONArray.toCollection(json, nvoidPerson.class);