Java:通过 Parse.com REST API 将日期对象作为 JSONObject 发送

Question

我正在尝试使用 HttpsUrlConnection 通过 Parse 的 REST API 在我的 Parse.com 数据库中创建一个新对象。他们的 REST API 只接受 JSON。我已经让一切正常工作，数据库将接受新的对象条目——除了我试图包含日期字段的时候。当我传入日期时，服务器完全拒绝该对象。

我在他们的文档中找到了这个关于在使用 REST API 时如何在对象中添加日期字段的描述:

The Parse mobile client libraries also support dates, binary data, and relational data. In the REST API, these values are encoded as JSON hashes with the __type field set to indicate their type, so you can read or write these fields if you use the correct encoding.

The Date type contains a field iso which contains a UTC timestamp stored in ISO 8601 format with millisecond precision: YYYY-MM-DDTHH:MM:SS.MMMZ.

{
  "__type": "Date",
  "iso": "2011-08-21T18:02:52.249Z"
}

因此，如果我想创建一个新对象并将其传递给数据库，我假设我需要创建另一个 JSONObject 并将其传递到相应的字段中。但是，当我尝试这样做时，它仍然拒绝了它。下面是我尝试添加 Date 对象作为传递参数，存储在它自己的 JSONObject 中。我究竟做错了什么？根据他们的文档，在 JSON 中发送 Date 对象的正确方法是什么？

//datePicked is a Calendar object
Date sendTime = datePicked.getTime();
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
formatter.setTimeZone(TimeZone.getTimeZone("UTC"));
String sendTimeInUTC = formatter.format(sendTime);  

//Storing the Date object as a JSONObject, as specified
JSONObject dateAsObj = new JSONObject();
dateAsObj.put("__type", "Date");
dateAsObj.put("iso", sendTimeInUTC);

//jsonParam is the JSONObject that is being sent over to Parse's REST API
jsonParam.put("sendTime", dateAsObj);

这是发出http请求的完整函数，供上下文和引用:

private void runHttpRequest(final String emailAddress, final String password,
        String[] recipients, final String title, final String message) throws MalformedURLException {
    //Stores email in Parse DB, from Java servlet
    String url = "https://api.parse.com/1/classes/Email";
    URL obj = new URL(url);
    HttpsURLConnection con = null;
    try {
        con = (HttpsURLConnection) obj.openConnection();
    } catch (IOException e) {
        System.out.println("Failed to connect to http link");
        e.printStackTrace();
    }

    //add request header
    try {
        con.setRequestMethod("POST");
    } catch (ProtocolException e) {
        System.out.println("Failed to set to POST");
        e.printStackTrace();
    }
    con.setRequestProperty("X-Parse-Application-Id", "*****************");
    con.setRequestProperty("X-Parse-REST-API-Key", "*******************");
    con.setRequestProperty("Content-Type", "application/json");

    JSONObject jsonParam = new JSONObject();
    jsonParam.put("username", "******");
    jsonParam.put("emailID", 1);
    jsonParam.put("universalID", "******");
    Gson converter = new Gson();
    String recipientsInJson = converter.toJson(recipients);
    jsonParam.put("to", recipientsInJson);
    jsonParam.put("from", emailAddress);
    jsonParam.put("title", title);
    jsonParam.put("body", message);

    Date sendTime = datePicked.getTime();
    //jsonParam.put("sendTime", sendTime);
    SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    formatter.setTimeZone(TimeZone.getTimeZone("UTC"));
    String sendTimeInUTC = formatter.format(sendTime);
    System.out.println("UTC time" + sendTimeInUTC);

    JSONObject dateAsObj = new JSONObject();
    dateAsObj.put("__type", "Date");
    dateAsObj.put("iso", sendTimeInUTC);
    System.out.println(dateAsObj.toString());

    jsonParam.put("sendTime", dateAsObj);

    String urlParameters = jsonParam.toString();

    // Send POST request
    con.setDoOutput(true);
    DataOutputStream wr = null;
    try {
        wr = new DataOutputStream(con.getOutputStream());
    } catch (IOException e1) {
        System.out.println("Failed to get output stream");
        e1.printStackTrace();
    }
    try {
        wr.writeBytes(urlParameters);
    } catch (IOException e) {
        System.out.println("Failed to connect to send over Parse object as parameter");
        e.printStackTrace();
    }
    try {
        wr.flush();
    } catch (IOException e) {
        e.printStackTrace();
    }
    try {
        wr.close();
    } catch (IOException e) {
        System.out.println("Failed to connect to close datastream connection");
        e.printStackTrace();
    }

    int responseCode = 0;
    try {
        responseCode = con.getResponseCode();
    } catch (IOException e) {
        System.out.println("Failed to connect to get response code");
        e.printStackTrace();
    }
    System.out.println("\nSending 'POST' request to URL : " + url);
    System.out.println("Post parameters : " + urlParameters);
    System.out.println("Response Code : " + responseCode);

    BufferedReader in = null;
    try {
        in = new BufferedReader(
                new InputStreamReader(con.getInputStream()));
    } catch (IOException e) {
        System.out.println("Failed to get input stream");
        e.printStackTrace();
    }
    String inputLine;
    StringBuffer response = new StringBuffer();

    try {
        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
    } catch (IOException e) {
        System.out.println("Failed to read line");
        e.printStackTrace();
    }
    try {
        in.close();
    } catch (IOException e) {
        System.out.println("Failed to close input stream");
        e.printStackTrace();
    }

    //print result
    System.out.println(response.toString());
}

如有任何帮助或意见，我们将不胜感激。

Answer 1

您的格式不符合他们要求的格式。例如:

Theirs: 2011-08-21T18:02:52.249Z
Yours:  2011-08-21 18:02:52.249

您缺少 T 和 Z。

所以尝试将格式更改为:

SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");

老实说，如果这不是自动处理的，我会感到惊讶 - 你试过 dateAsObj.put("iso", sendTime) 吗？