How can i parse JSON from Webservice result with Gson

问题

When i send request to server. I get result data with this format:

{
"menu": {
    "7": [{
        "m_id": "1",
        "m_flag": "1",
        "m_type": "7",
        "m_name": "\u30cf\u30a4\u30cd\u30b1\u30f3",
        "m_price": "1000",
        "m_cost": "158",
        "m_regist_date": "0000-00-00",
        "p_id": "0"
    }, {
        "m_id": "2",
        "m_flag": "1",
        "m_type": "7",
        "m_name": "\u30ae\u30cd\u30b9",
        "m_price": "1000",
        "m_cost": "250",
        "m_regist_date": "0000-00-00",
        "p_id": "0"
    },....
    "2": [{
        "m_id": "149",
        "m_flag": "1",
        "m_type": "2",
        "m_name": "\u30da\u30fc\u30bf\u30fc\u30e4\u30b3\u30d6\u30ea\u30fc\u30b9\u30ea\u30f3\u30b0",
        "m_price": "6500",
        "m_cost": "2100",
        "m_regist_date": "0000-00-00",
        "p_id": "0"
    }, {
        "m_id": "150",
        "m_flag": "1",
        "m_type": "2",
        "m_name": "\u30a4\u30d3\u30b9\u30af\u30b9 \u30eb\u30fc\u30b8\u30e5 08",
        "m_price": "6800",
        "m_cost": "2520",
        "m_regist_date": "0000-00-00",
        "p_id": "0"
    },...
}

It very long . So when i used :

JSONObject json = jsonParser.makeHttpRequest(REQUEST_URL, "POST",params);
menu = json.getJSONArray("menu");

I get error and can't get data of JSON:

Error parsing data org.json.JSONException: End of input at character 0 of 

How can i Parse data of json , I do not know how to use Gson. AND how can i get data of KEY "2". Thank you very much!

回答1:

If you are looking for GSON parsing then find it here.

Simply create a POJO class and map it to JSON string.

Sample code:

class MenuDetail {
    private String m_id;
    private String m_flag;
    private String m_type;
    private String m_name;
    private String m_price;
    private String m_cost;
    private String m_regist_date;
    private String p_id;
    // getter & setter
}

...

Type type = new TypeToken<Map<String, Map<String, ArrayList<MenuDetail>>>>() {}.getType();
Map<String, Map<String, ArrayList<MenuDetail>>> data = new Gson().fromJson(json, type);

System.out.println(new GsonBuilder().setPrettyPrinting().create().toJson(data));

output:

{
  "menu": {
    "7": [
      {
        "m_id": "1",
        "m_flag": "1",
        "m_type": "7",
        "m_name": "name",
        "m_price": "1000",
        "m_cost": "158",
        "m_regist_date": "0000-00-00",
        "p_id": "0"
      },
      {
        "m_id": "2",
        "m_flag": "1",
        "m_type": "7",
        "m_name": "name",
        "m_price": "1000",
        "m_cost": "250",
        "m_regist_date": "0000-00-00",
        "p_id": "0"
      }
    ]
  }
}

来源：https://stackoverflow.com/questions/24133110/how-can-i-parse-json-from-webservice-result-with-gson