如何保存以.json文件排序的数据，应该存储在哪里，以及如何检索它？

I'm new to android developing and created an "eventlogger" app where you start by choosing an infinite number of Events in this Activity:

我是Android新手,开发并创建了一个“eventlogger”应用程序,您可以在此活动中选择无限数量的事件:

All the Events are added into an ArrayList called "events" that looks like that:

所有事件都被添加到名为“events”的ArrayList中,如下所示:

[Event 1, Event 2, Event 3]

In the next Activity you can start a timer, press the buttons and log the times as strings into an Arraylist of Arraylists.

在下一个Activity中,你可以启动一个计时器,按下按钮并将时间作为字符串记录到Arraylists的Arraylist中。

The ArrayList of Arraylists is named "allEventsList" is created

Arraylists的ArrayList被命名为“allEventsList”被创建

ArrayList<ArrayList<String>> allActionsList;

and then filled with data (times), so it looks like that

然后填充数据(次),所以它看起来像那样

[[00:00:01, 00:00:09, 00:00:12], [00:00:04, 00:00:07, 00:00:14], [00:00:03, 00:00:06, 00:00:15]]

At the end I want to safe that in a .json file that looks like that

最后,我想在一个看起来像这样的.json文件中保护它

{
"events":{
    "Event 1":["00:00:01", "00:00:09", "00:00:12"],
    "Event 2":["00:00:04", "00:00:07", "00:00:14"],
    "Event 3":["00:00:03", "00:00:06", "00:00:15"]

}

How can I write my data in a .json file and how can I retrieve it later on and where should I store it?

如何在.json文件中编写数据,如何在以后检索它以及在哪里存储它?

1 个解决方案

#1

Here you have a way to do it:

在这里你有办法做到这一点:

private String convertToJsonString(ArrayList<ArrayList<String>> allActionsList) 
{
    JSONObject jObj = new JSONObject();
    JSONObject events = new JSONObject();
    JSONArray eventX;
    int count = 1;
    String key;

    try {
        for(ArrayList<String> array : allActionsList){
            key = String.format("Event %d", count);
            eventX = new JSONArray();
            for(String s : array){
                eventX.put(s);
            }
            events.put(key, eventX);
            count++;
        }
        jObj.put("events", events);

    } catch(Exception e){
        // failed somewhere to create JSON object
        e.printStackTrace();
    }
    return jObj.toString();
}

After converting to String you can just save it to a file.

转换为String后,您只需将其保存到文件即可。

Then you can read it back from file as a string and build your JSON object back like this:

然后你可以将它作为字符串从文件中读回来并像这样构建你的JSON对象:

JSONObject events = new JSONObject(<string read from file>);

Hope this works for you.

希望这对你有用。

#1