android - 如何将 Json 对象附加到 android 中现有的 json 文件中

Question

我的 json 文件包含，

{
  "appointments": [
    {
      "appointmentId": "app_001",
      "appointmentTitle": "Appointment Title1",
      "appointmentDate": "2017-11-25",
      "appointmentTime": "10:30",
      "appointmentStatus": "active",
      "appointmentType": "meeting",
      "reminder": {
        "type": "notification",
        "time": "10:15",
        "status": "off"
      },
      "appointmentDescription": "blablablablabla1"
    },
    {
      "appointmentId": "app_002",
      "appointmentTitle": "AppointmentTitle2",
      "appointmentDate": "2017-11-26",
      "appointmentTime": "09:00",
      "appointmentStatus": "done",
      "appointmentType": "exam",
      "reminder": {
        "type": "alarm",
        "time": "08:45",
        "status": "on"
      },
      "appointmentDescription": "blablablablabla2"
    }
  ]
}

我需要将另一个 jsonobject 放入数组中，输出应该是这样的，

{
  "appointments": [
    {
      "appointmentId": "app_001",
      "appointmentTitle": "Appointment Title1",
      "appointmentDate": "2017-11-25",
      "appointmentTime": "10:30",
      "appointmentStatus": "active",
      "appointmentType": "meeting",
      "reminder": {
        "type": "notification",
        "time": "10:15",
        "status": "off"
      },
      "appointmentDescription": "blablablablabla1"
    },
    {
      "appointmentId": "app_002",
      "appointmentTitle": "AppointmentTitle2",
      "appointmentDate": "2017-11-26",
      "appointmentTime": "09:00",
      "appointmentStatus": "done",
      "appointmentType": "exam",
      "reminder": {
        "type": "alarm",
        "time": "08:45",
        "status": "on"
      },
      "appointmentDescription": "blablablablabla2"
    },
    {
      "appointmentId": "app_003",
      "appointmentTitle": "AppointmentTitle3",
      "appointmentDate": "2017-11-26",
      "appointmentTime": "09:00",
      "appointmentStatus": "done",
      "appointmentType": "exam",
      "reminder": {
        "type": "alarm",
        "time": "08:45",
        "status": "on"
      },
      "appointmentDescription": "blablablablabla3"
    }
  ]
}

我使用以下代码段执行我的要求。

File fileJson = new File(getApplicationContext().getExternalFilesDir("/app"), "app.json");

String strFileJson = getStringFromFile(fileJson.toString());

JSONObject jsonObj = new JSONObject(strFileJson);

jsonObj.put("appointmentId", "app_002");
jsonObj.put("appointmentTitle", "Appointment Title2");
jsonObj.put("appointmentDate", "2017-11-21");
jsonObj.put("appointmentTime", "01:30");
jsonObj.put("appointmentStatus", "active");
jsonObj.put("appointmentType", "meeting");

JSONObject reminder = new JSONObject();
reminder.put("type", "note");
reminder.put("time", "12:30");
reminder.put("status", "off");
jsonObj.put("reminder", reminder);
jsonObj.put("appointmentDescription", "blablablablabla2");

writeJsonFile(fileJson, jsonObj.toString()); 

writeJsonFile、getStringFromFile、convertStreamToString函数是，

public static String getStringFromFile(String filePath) throws Exception {
    File fl = new File(filePath);
    FileInputStream fin = new FileInputStream(fl);
    String ret = convertStreamToString(fin);
    //Make sure you close all streams.
    fin.close();
    return ret;
}

public static String convertStreamToString(InputStream is) throws Exception {
    BufferedReader reader = new BufferedReader(new InputStreamReader(is));
    StringBuilder sb = new StringBuilder();
    String line = null;
    while ((line = reader.readLine()) != null) {
        sb.append(line).append("\n");
    }
    return sb.toString();
}

public static void writeJsonFile(File file, String json) {
    BufferedWriter bufferedWriter = null;
    try {

        if (!file.exists()) {
            Log.e("App","file not exist");
            file.createNewFile();
        }

        FileWriter fileWriter = new FileWriter(file);
        bufferedWriter = new BufferedWriter(fileWriter);
        bufferedWriter.write(json);

    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            if (bufferedWriter != null) {
                bufferedWriter.close();
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }
}

但我得到的输出是，

{
  "appointments": [
    {
      "appointmentId": "app_001",
      "appointmentTitle": "Appointment Title1",
      "appointmentDate": "2017-11-25",
      "appointmentTime": "10:30",
      "appointmentStatus": "active",
      "appointmentType": "meeting",
      "reminder": {
        "type": "notification",
        "time": "10:15",
        "status": "off"
      },
      "appointmentDescription": "blablablablabla1"
    },
    {
      "appointmentId": "app_002",
      "appointmentTitle": "AppointmentTitle2",
      "appointmentDate": "2017-11-26",
      "appointmentTime": "09:00",
      "appointmentStatus": "done",
      "appointmentType": "exam",
      "reminder": {
        "type": "alarm",
        "time": "08:45",
        "status": "on"
      },
      "appointmentDescription": "blablablablabla2"
    }
  ],
  "appointmentId": "app_002",
  "appointmentTitle": "Appointment Title2",
  "appointmentDate": "2017-11-21",
  "appointmentTime": "01:30",
  "appointmentStatus": "active",
  "appointmentType": "meeting",
  "reminder": {
    "type": "note",
    "time": "12:30",
    "status": "off"
  },
  "appointmentDescription": "blablablablabla2"
}

请帮助我获得所需的 json 格式作为输出。提前致谢

Answer 1

希望这会做你想做的，替换你的

JSONObject jsonObj = new JSONObject(strFileJson);

jsonObj.put("appointmentId", "app_002");
jsonObj.put("appointmentTitle", "Appointment Title2");
jsonObj.put("appointmentDate", "2017-11-21");
jsonObj.put("appointmentTime", "01:30");
jsonObj.put("appointmentStatus", "active");
jsonObj.put("appointmentType", "meeting");

JSONObject reminder = new JSONObject();
reminder.put("type", "note");
reminder.put("time", "12:30");
reminder.put("status", "off");
jsonObj.put("reminder", reminder);
jsonObj.put("appointmentDescription", "blablablablabla2");

有了这个，

JSONObject PreviousJsonObj = new JSONObject(strFileJson);
JSONArray array = PreviousJsonObj.getJSONArray("appointments");
JSONObject jsonObj= new JSONObject();

jsonObj.put("appointmentId", "app_002");
jsonObj.put("appointmentTitle", "Appointment Title2");
jsonObj.put("appointmentDate", "2017-11-21");
jsonObj.put("appointmentTime", "01:30");
jsonObj.put("appointmentStatus", "active");
jsonObj.put("appointmentType", "meeting");

JSONObject reminder = new JSONObject();
reminder.put("type", "note");
reminder.put("time", "12:30");
reminder.put("status", "off");
jsonObj.put("reminder", reminder);
jsonObj.put("appointmentDescription", "blablablablabla2");
array.put(jsonObj);

JSONObject currentJsonObject = new JSONObject();
currentJsonObject.put("appointments",array);