如何反序列化的JSON / GSON这可能是一个字符串，对象或列表 [英] how to deserialize a json/gson that could be a string , object ,or list

问题描述

我有以下的JSON

"notes": {"note": [
         {
             "content": "Having wisdom teeth removed.",
             "from": "employee"
         },
         {
             "content": "Get well soon",
             "from": "manager"
         }
     ]},

的问题是，值也coud是

the issue is that the value coud also be

 "notes": "",

或

"notes": {"note": {
            "content": "This is a test note.",
            "from": "employee"
        }},

和将其存储在这些

public  class Notes
{
    @SerializedName ("note")
    public List<Note> note;
}
public  class Note
{
    @SerializedName ("content")
    public String content;
    @SerializedName ("from")
    public String from;
}

我相信我解决的不是一个数组但这样做是一个单一对象的问题

I believe I solved the issue of not being an array but being an single object by doing this

public class Json {
    private static Gson gson;

    private static class MyNoteClassTypeAdapter implements JsonDeserializer<List<RequestsDTO.Note>> {
        public List<RequestsDTO.Note> deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext ctx) {
            List<RequestsDTO.Note> vals = new ArrayList<RequestsDTO.Note>();
            if (json.isJsonArray()) {
                for (JsonElement e : json.getAsJsonArray()) {
                    vals.add((RequestsDTO.Note) ctx.deserialize(e, RequestsDTO.Note.class));
                }
            } else if (json.isJsonObject()) {
                vals.add((RequestsDTO.Note) ctx.deserialize(json,RequestsDTO.Note.class));
            } else {
                throw new RuntimeException("Unexpected JSON type: " + json.getClass());
            }
            return vals;
        }
    }

    public static Gson getGson()
    {
        if (gson == null)
        {
            Type ListType = new TypeToken<List<RequestsDTO.Note>>() {}.getType();
            GsonBuilder builder = new GsonBuilder();
            builder.registerTypeAdapter(DateTime.class, new DateTimeSerializer());
            builder.registerTypeAdapter(ListType, new MyNoteClassTypeAdapter());
            gson = builder.create();
        }
        return gson;
    }
}

而现在我坚持的时候，整个事情刚回来作为字符串上......

And now I am stuck on when the whole thing just comes back as a string....

推荐答案

我们的想法是尽量让音符字段（从注意事项 的JSONObject ）的 JSONArray 第一，如果它抛出异常，这将意味着有没有注意 JSONArray 到音符 的JSONObject ，这将意味着音符是的JSONObject 。我们可以计算出状况时，注字段是用同样的方法字符串。

The idea is try to get "note" field (from "notes" JSONObject) as JSONArray first and if it throws exception that will mean that there is no "note" JSONArray into "notes" JSONObject and that will mean that "note" is JSONObject. The same way we can figure out situation when note field is String.

try {
        //String jsonString="{\"notes\": {\"note\": [{\"content\": \"Having wisdom teeth removed.\",\"from\": \"employee\" }, {\"content\": \"Get well soon\", \"from\": \"manager\"} ] }}";
        //String jsonString="{\"notes\": { \"note\": {\"content\": \"This is a test note.\",\"from\": \"employee\"}}}";
        String jsonString="{\"notes\": { \"note\": \"\"}}";

        JSONObject jsonObject=new JSONObject(jsonString);
        JSONObject jsonObjectNotes=jsonObject.getJSONObject("notes");

        try{
            JSONArray jsonArrayNote=jsonObjectNotes.getJSONArray("note");
            for (int i = 0; i < jsonArrayNote.length(); i++) {

                JSONObject jsonObject2= jsonArrayNote.getJSONObject(i);
                String stringContent=jsonObject2.getString( "content");
                String stringFrom= jsonObject2.getString( "from");

                Log.e(getClass().getName(), "content="+stringContent +"; from="+stringFrom);
            }
        }
        catch(JSONException e){
            //that means that jsonObjectNotes has no jsonArray with name "notes" and "notes" is jsonObject
            try{
                JSONObject jsonObject3=jsonObjectNotes.getJSONObject("note");

                String stringContent=(String) jsonObject3.get( "content");
                String stringFrom=(String) jsonObject3.get( "from");

                Log.e(getClass().getName(), "content="+stringContent +"; from="+stringFrom);
            }
            catch(JSONException ex){
                //that means that jsonObjectNotes has no jsonObject with name "notes" and "notes" is empty String
                String stringNote=jsonObjectNotes.getString("note") ;       
                Log.e(getClass().getName(), "note is string ="+ stringNote);
            }
        }

    } catch (JSONException e) {
        e.printStackTrace();
    }

在我的例子code另一个 GET 的操作也会抛出jsonExceptions但我认为你的想法。

In my example code another get operations can also throw jsonExceptions but I think you get the idea.

这篇关于如何反序列化的JSON / GSON这可能是一个字符串，对象或列表的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！