使用 GSON 的 Android JSON 解析数组

Question

一天中的大部分时间我都在与 GSON 作斗争。好吧，与其说是 GSON，不如说是我对 Android 列表的一般不了解。基本上发生的事情是我收到 2 个 JSON 数组，然后每个数组都将被格式化并显示在列表中:

Adventures:
+-------------+
| Adventure 1 |
+-------------+
| Adventure 2 |
+-------------+
Events:
+-------------+
|   Event 1   |
+-------------+
|   Event 2   |
+-------------+

我能够很好地读出单个字符串，但我没有考虑将其移至数组。我收到的 JSON 格式是:

{
"events": [
    {
        "eid": "11111111",
        "bid": "aaaaaaaa",
        "bname": "Example Business 1",
        "start": "3/26/14 @ 6pm",
        "end": "3/27/14 @ 2am",
        "points": "50",
        "title": "Example Event 1",
        "description": "Example Event Description",
        "cat": "Nightlife",
        "type": "Bar",
        "subtype": "Karaoke",
        "valid": true
    },
    {
        "eid": "22222222",
        "bid": "bbbbbbbb",
        "bname": "Example Business 2",
        "start": "3/26/14 @ 6pm",
        "end": "3/27/14 @ 2am",
        "points": "50",
        "title": "Example Event 2",
        "description": "Example Event Description",
        "cat": "Nightlife",
        "type": "Comedy",
        "subtype": "General",
        "valid": true
    },
    {
        "eid": "33333333",
        "bid": "cccccccc",
        "bname": "Example Business 3",
        "start": "3/26/14 @ 6pm",
        "end": "3/27/14 @ 2am",
        "points": "150",
        "title": "Example Event 3",
        "description": "Example Event Description",
        "cat": "Dining",
        "type": "Restraunt",
        "subtype": "Chinese",
        "valid": true
    }
],
"adventures": [
    {
        "aid": "11111111",
        "bid": "aaaaaaaa",
        "start": "3/26/14 6pm",
        "end": "3/27/14 2am",
        "points": "150",
        "title": "Example Adventure 1",
        "description": "Example Adventure Description",
        "cat": "Nightlife",
        "type": "Bar",
        "subtype": "Karaoke",
        "steps_comp": "2",
        "total_steps": "5",
        "valid": true
    },
    {
        "aid": "22222222",
        "bid": "bbbbbbbb",
        "start": "3/26/14 6pm",
        "end": "3/27/14 2am",
        "points": "250",
        "title": "Example Adventure 2",
        "description": "Example Adventure Description",
        "cat": "Nightlife",
        "type": "Bar",
        "subtype": "Neighborhood",
        "steps_comp": "0",
        "total_steps": "5",
        "valid": true
    }
]

我正在使用以下内容解析 JSON(包括 Volley 代码):

RequestQueue queue = Volley.newRequestQueue(this);
    JsonObjectRequest jsObjRequest = new JsonObjectRequest(Request.Method.GET, full_url, null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {
            String example = response.toString();
            Log.e("JSON Response", example);

            try {
                JsonParser jsonParser = new JsonParser();
                JsonObject jo = (JsonObject)jsonParser.parse(example);
                JsonArray jsonArr = jo.getAsJsonArray("events");
                //jsonArr.
                Gson googleJson = new Gson();
                ArrayList jsonObjList = googleJson.fromJson(jsonArr, ArrayList.class);

                System.out.println("List size is : "+jsonObjList.size());
                System.out.println("List Elements are  : "+jsonObjList.toString());

                for (int i = 0; i < jsonObjList.size(); i++){
                       String item = jsonObjList.get(i).toString();
                       System.out.println("Item " + i + " : " + item);
                }

                Toast.makeText(getApplicationContext(), "0: "+jsonObjList.get(0),
                        Toast.LENGTH_LONG).show();
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            Toast.makeText(getApplicationContext(), "blah",
               Toast.LENGTH_LONG).show();
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            // TODO Auto-generated method stub
        }
    }
);
queue.add(jsObjRequest);

我得到的每一行都很好，但它只是一个字符串，所以我无法获取每一行的各个元素。我在想我可能需要在 for 循环中进行另一个 GSON 调用来打破那个循环，然后放置在数组中？这看起来很乱。我已经做了一些 googleing(我是如何走到这一步的)，但我似乎无法将各个部分放在一起来完成这个工作。任何帮助将不胜感激。

Answer 1

首先为每个 JsonAarry 创建类来保存值

public class Events {
    private String eid;
    private String bid;
    private String bname;
    private String start;
    private String end;
    private String points;
    private String title;
    private String description;
    private String cat;
    private String type;
    private String subtype;
    private boolean valid;
    @Override
    public String toString() {
        return "Events [eid=" + eid + ", bid=" + bid + ", bname=" + bname
                + ", start=" + start + ", end=" + end + ", points=" + points
                + ", title=" + title + ", description=" + description
                + ", cat=" + cat + ", type=" + type + ", subtype=" + subtype
                + ", valid=" + valid + "]";
    }

}

和

public class Adventures {
    private String aid;
    private String bid;
    private String start;
    private String end;
    private String points;
    private String title;
    private String description;
    private String cat;
    private String type;
    private String subtype;
    private String steps_comp;
    @Override
    public String toString() {
        return "Adventures [aid=" + aid + ", bid=" + bid + ", start=" + start
                + ", end=" + end + ", points=" + points + ", title=" + title
                + ", description=" + description + ", cat=" + cat + ", type="
                + type + ", subtype=" + subtype + ", steps_comp=" + steps_comp
                + ", total_steps=" + total_steps + ", valid=" + valid + "]";
    }
    private String total_steps;
    private boolean valid;

}

现在创建一个包含整个响应的类

public class ResponseHolder {
    private ArrayList<Events> events;
    private ArrayList<Adventures> adventures;
    @Override
    public String toString() {
        return "ResponseHolder [events=" + events + ", adventures="
                + adventures + "]";
    }
    public ArrayList<Events> getEvents() {
        return events;
    }
    public ArrayList<Adventures> getAdventures() {
        return adventures;
    }
}

最后

Gson googleJson = new Gson();
ResponseHolder rh= googleJson.fromJson(jsonArr, ResponseHolder.class);

并获取类似的数据

        for(Events e: rh.getEvents()){
            System.out.println(e.toString());
        }

        for(Adventures e: rh.getAdventures()){
            System.out.println(e.toString());
        }