如何读取 java 中的嵌套 json 列表？

Question

I need to get type value and networkUsage download value and list was dynamic

Json Response was

    {
  "count": 2,
  "devices": [
    {
      "name": "xyz",
      "type": 1,
      "subType": 0,
      "signalStrength": -37,
      "dataUsage": {
        "download": 84,
        "upload": 84
      },
      "networkUsage": {
        "download": 0,
        "upload": 0
      },
      "speed": {
        "download": 0,
        "upload": 0
      }
    },
    {
      "name": "abcd",
      "type": 2,
      "subType": 0,
      "signalStrength": -37,
      "dataUsage": {
        "download": 84,
        "upload": 84
      },
      "networkUsage": {
        "download": 0,
        "upload": 0
      },
      "speed": {
        "download": 0,
        "upload": 0
      }
    }
  ]
}

I tried this way and got errors.

JSONArray jsonarray = new JSONArray(response);
System.out.println(String.format("JSONArray length => %d", jsonarray.length()));

for (int i = 0; i < jsonarray.length(); i++) {
        JSONObject obj1 = jsonarray.getJSONObject(i);
        String name = obj1.getString("name");
        int type = obj1.getInt("type");
        System.out.println(name);
        System.out.println(type);
}

Exception in thread "main" org.json.JSONException: A JSONArray text must start with '[' at character 1 at org.json.JSONTokener.syntaxError(JSONTokener.java:496) at org.json.JSONArray.(JSONArray.java:115) at org.json.JSONArray.(JSONArray.java:159) at com.calix.pages.test.main(test.java:91)

Answer 1

JSONObject jsonobj = new JSONObject(response);
JSONArray jsonarray = jsonobj.getJSONArray("devices");
for (int i = 0; i < jsonobj.getInt("count"); i++) {
        JSONObject obj1 = jsonarray.getJSONObject(i);
        String name = obj1.getString("name");
        int type = obj1.getInt("type");
        System.out.println(name);
        System.out.println(type);
}