在Java中讀取具有多個對象的json文件

Question

我寫了一個程序，讀取一個簡單的json文件：

public static void main(String[] args) {
    JSONParser parser = new JSONParser();
    try {
        JSONArray a = (JSONArray) parser.parse(new FileReader("C:/Users/Zonoid/Desktop/EQ.json"));
        for (Object o : a)
        {
            JSONObject obj = (JSONObject) o;
            String city = (String) obj.get("CITY");
            System.out.println("City : " + city);
            String loc = (String) obj.get("LOCATION");
            System.out.println("Location : " + loc);
            long el = (Long) obj.get("E_LEVEL");
            System.out.println("Emergency Level : " + el);
            long depth = (Long) obj.get("DEPTH");
            System.out.println("Depth : " + depth);
            long i = (Long) obj.get("INTENSITY");
            System.out.println("Intensity :"+i);
            System.out.println("\n");
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (ParseException e) {
        e.printStackTrace();
    }
}

我的json文件是：

[{"CITY":"MUMBAI","LOCATION":"a" ,"E_LEVEL": 6,"DEPTH":10,"INTENSITY":5},
{"CITY":"MUMBAI","LOCATION":"b" ,"E_LEVEL": 8,"DEPTH":20,"INTENSITY":4},
{"CITY":"MUMBAI","LOCATION":"c" ,"E_LEVEL": 3,"DEPTH":13,"INTENSITY":5},
{"CITY":"MUMBAI","LOCATION":"d" ,"E_LEVEL": 6,"DEPTH":12,"INTENSITY":4},]

我正在一個處理地震警報的項目，並且想讀取其JSON文件，但是無法將其導入JSON數組中。 我要導入的文件如下所示：

{
  "type": "FeatureCollection",
  "metadata": {
    "generated": 1488472809000,
    "url": "https:\/\/earthquake.usgs.gov\/earthquakes\/feed\/v1.0\/summary\/significant_week.geojson",
    "title": "USGS Significant Earthquakes, Past Week",
    "status": 200,
    "api": "1.5.4",
    "count": 2
  },
  "features": [
    {
      "type": "Feature",
      "properties": {
        "mag": 5.5,
        "place": "42km WSW of Anchor Point, Alaska",
        "time": 1488420690658,....

請告訴我們應該進行哪些更改。

Answer 1

如果僅嘗試讀取功能，則首先需要將整個文件作為對象讀取。 然后，您可以通過以下方式讀取數組部分：

Object object = parser.parse(new FileReader("C:/Users/Zonoid/Desktop/EQ.json"));
JSONObject jasonObject = (JSONObject) object;
JSONArray features = (JSONArray) jasonObject.get("features");