在Android中以JSON格式解析數據時出現此錯誤

Question

我收到此錯誤：

org.json.JSONException：類型java.lang.String的值http無法轉換為JSONObject

public class QueryUtils {

    private QueryUtils(){

    }

    //private static final String URL = "http://earthquake.usgs.gov/fdsnws/event/1/query?format=geojson&starttime=2016-01-01&endtime=2016-01-31&minmag=6&limit=10";

    public static ArrayList<Earthquake> extractEarthquakes() {

         String URL = "http://earthquake.usgs.gov/fdsnws/event/1/query?format=geojson&starttime=2016-01-01&endtime=2016-01-31&minmag=6&limit=10";

        ArrayList<Earthquake> earthquakes = new ArrayList<Earthquake>();

        try {

            String responseDate = URL.toString();
            JSONObject rootObject = new JSONObject(responseDate);
            JSONArray features = rootObject.getJSONArray("features");

//           Date dateObject;
//            SimpleDateFormat simpleDateFormat = new SimpleDateFormat("MMM DD,yyyy h:mm a", Locale.ENGLISH);

            //iterate through loop to display each value

            for(int i=0; i <features.length(); i++){
                JSONObject jsonObjectForDetails = features.getJSONObject(i);

                JSONObject jsonObjectForProperties = jsonObjectForDetails.getJSONObject("properties");

//                double magValue = double.parseInt(jsonObjectForProperties.optString("mag").toString());
//                String addressDetails = jsonObjectForProperties.optString("place").toString();
//                int dateDetails = Integer.parseInt(jsonObjectForProperties.optString("time").toString());

                double magValue = jsonObjectForProperties.getDouble("mag");
                String addressDetails = jsonObjectForProperties.getString("place");
                long  dateDetails = jsonObjectForProperties.getLong("time");

               // dateObject = new Date(dateDetails);
               // long  dateToDisplay = simpleDateFormat.format(dateObject);
                earthquakes.add(new Earthquake(magValue,addressDetails,dateDetails));

            }

        } catch (JSONException e) {
            Log.e("QueryUtils", "Problem parsing the earthquake JSON results", e);
        }

        return earthquakes;
    }

}

Answer 1

總結其他評論：

要從url檢索數據，請使用以下功能：

public static String getJsonFromServer(String url) throws IOException {

    BufferedReader inputStream = null;

    URL jsonUrl = new URL(url);
    URLConnection dc = jsonUrl.openConnection();

    dc.setConnectTimeout(5000);
    dc.setReadTimeout(5000);

    inputStream = new BufferedReader(new InputStreamReader(
            dc.getInputStream()));

    // read the JSON results into a string
    String jsonResult = inputStream.readLine();
    return jsonResult;
}

供您使用

 try {
            String responseDate= getJsonFromServer(URL);
//the other code:
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

而不是String responseDate = URL.toString();

並且此代碼（用於json解析）也適用：

import org.json.JSONArray;
import org.json.JSONObject;


    public class EarthQuakeTest {
        //http://earthquake.usgs.gov/fdsnws/event/1/query?format=geojson&starttime=2016-01-01&endtime=2016-01-31&minmag=6&limit=10
        private static final String str = "{\"type\":\"FeatureCollection\",\"metadata\":{\"generated\":1475336259000,\"url\":\"http://earthquake.usgs.gov/fdsnws/event/1/query?format=geojson&starttime=2016-01-01&endtime=2016-01-31&minmag=6&limit=10\",\"title\":\"USGS Earthquakes\",\"status\":200,\"api\":\"1.5.2\",\"limit\":10,\"offset\":1,\"count\":10},\"features\":[{\"type\":\"Feature\",\"properties\":{\"mag\":7.2,\"place\":\"88km N of Yelizovo, Russia\",\"time\":1454124312220,\"updated\":1463685050282,\"tz\":720,\"url\":\"http://earthquake.usgs.gov/earthquakes/eventpage/us20004vvx\",\"detail\":\"http://earthquake.usgs.gov/fdsnws/event/1/query?eventid=us20004vvx&format=geojson\",\"felt\":2,\"cdi\":3.4,\"mmi\":5.82,\"alert\":\"green\",\"status\":\"reviewed\",\"tsunami\":1,\"sig\":798,\"net\":\"us\",\"code\":\"20004vvx\",\"ids\":\",gcmt20160130032510,at00o1qxho,pt16030050,us20004vvx,gcmt20160130032512,\",\"sources\":\",gcmt,at,pt,us,gcmt,\",\"types\":\",associate,cap,dyfi,finite-fault,general-link,general-text,geoserve,impact-link,impact-text,losspager,moment-tensor,nearby-cities,origin,phase-data,shakemap,tectonic-summary,\",\"nst\":null,\"dmin\":0.958,\"rms\":1.19,\"gap\":17,\"magType\":\"mww\",\"type\":\"earthquake\",\"title\":\"M 7.2 - 88km N of Yelizovo, Russia\"},\"geometry\":{\"type\":\"Point\",\"coordinates\":[158.5463,53.9776,177]},\"id\":\"us20004vvx\"},\r\n{\"type\":\"Feature\",\"properties\":{\"mag\":6.1,\"place\":\"94km SSE of Taron, Papua New Guinea\",\"time\":1453777820750,\"updated\":1466450055338,\"tz\":600,\"url\":\"http://earthquake.usgs.gov/earthquakes/eventpage/us20004uks\",\"detail\":\"http://earthquake.usgs.gov/fdsnws/event/1/query?eventid=us20004uks&format=geojson\",\"felt\":null,\"cdi\":null,\"mmi\":4.1,\"alert\":\"green\",\"status\":\"reviewed\",\"tsunami\":1,\"sig\":572,\"net\":\"us\",\"code\":\"20004uks\",\"ids\":\",gcmt20160126031023,us20004uks,gcmt20160126031020,\",\"sources\":\",gcmt,us,gcmt,\",\"types\":\",associate,cap,geoserve,losspager,moment-tensor,nearby-cities,origin,phase-data,shakemap,tectonic-summary,\",\"nst\":null,\"dmin\":1.537,\"rms\":0.74,\"gap\":25,\"magType\":\"mww\",\"type\":\"earthquake\",\"title\":\"M 6.1 - 94km SSE of Taron, Papua New Guinea\"},\"geometry\":{\"type\":\"Point\",\"coordinates\":[153.2454,-5.2952,26]},\"id\":\"us20004uks\"},\r\n{\"type\":\"Feature\",\"properties\":{\"mag\":6.3,\"place\":\"50km NNE of Al Hoceima, Morocco\",\"time\":1453695722730,\"updated\":1466450270946,\"tz\":0,\"url\":\"http://earthquake.usgs.gov/earthquakes/eventpage/us10004gy9\",\"detail\":\"http://earthquake.usgs.gov/fdsnws/event/1/query?eventid=us10004gy9&format=geojson\",\"felt\":117,\"cdi\":7.2,\"mmi\":5.28,\"alert\":\"green\",\"status\":\"reviewed\",\"tsunami\":0,\"sig\":695,\"net\":\"us\",\"code\":\"10004gy9\",\"ids\":\",gcmt20160125042203,us10004gy9,gcmt20160125042202,\",\"sources\":\",gcmt,us,gcmt,\",\"types\":\",associate,cap,dyfi,geoserve,impact-text,losspager,moment-tensor,nearby-cities,origin,phase-data,shakemap,tectonic-summary,\",\"nst\":null,\"dmin\":2.201,\"rms\":0.92,\"gap\":20,\"magType\":\"mww\",\"type\":\"earthquake\",\"title\":\"M 6.3 - 50km NNE of Al Hoceima, Morocco\"},\"geometry\":{\"type\":\"Point\",\"coordinates\":[-3.6818,35.6493,12]},\"id\":\"us10004gy9\"},\r\n{\"type\":\"Feature\",\"properties\":{\"mag\":7.1,\"place\":\"86km E of Old Iliamna, Alaska\",\"time\":1453631430230,\"updated\":1469293028539,\"tz\":-540,\"url\":\"http://earthquake.usgs.gov/earthquakes/eventpage/us10004gqp\",\"detail\":\"http://earthquake.usgs.gov/fdsnws/event/1/query?eventid=us10004gqp&format=geojson\",\"felt\":1816,\"cdi\":7.2,\"mmi\":6.6,\"alert\":\"green\",\"status\":\"reviewed\",\"tsunami\":1,\"sig\":1496,\"net\":\"us\",\"code\":\"10004gqp\",\"ids\":\",at00o1gd6r,us10004gqp,ak12496371,gcmt20160124103030,\",\"sources\":\",at,us,ak,gcmt,\",\"types\":\",cap,dyfi,finite-fault,general-link,general-text,geoserve,impact-link,impact-text,losspager,moment-tensor,nearby-cities,origin,phase-data,shakemap,tectonic-summary,trump-origin,\",\"nst\":null,\"dmin\":0.72,\"rms\":2.11,\"gap\":19,\"magType\":\"mww\",\"type\":\"earthquake\",\"title\":\"M 7.1 - 86km E of Old Iliamna, Alaska\"},\"geometry\":{\"type\":\"Point\",\"coordinates\":[-153.4051,59.6363,129]},\"id\":\"us10004gqp\"},\r\n{\"type\":\"Feature\",\"properties\":{\"mag\":6.6,\"place\":\"215km SW of Tomatlan, Mexico\",\"time\":1453399617650,\"updated\":1466450324948,\"tz\":-420,\"url\":\"http://earthquake.usgs.gov/earthquakes/eventpage/us10004g4l\",\"detail\":\"http://earthquake.usgs.gov/fdsnws/event/1/query?eventid=us10004g4l&format=geojson\",\"felt\":11,\"cdi\":2.7,\"mmi\":3.92,\"alert\":\"green\",\"status\":\"reviewed\",\"tsunami\":1,\"sig\":673,\"net\":\"us\",\"code\":\"10004g4l\",\"ids\":\",gcmt20160121180659,at00o1bebo,pt16021050,us10004g4l,gcmt20160121180657,\",\"sources\":\",gcmt,at,pt,us,gcmt,\",\"types\":\",associate,cap,dyfi,geoserve,impact-link,impact-text,losspager,moment-tensor,nearby-cities,origin,phase-data,shakemap,tectonic-summary,\",\"nst\":null,\"dmin\":2.413,\"rms\":0.98,\"gap\":74,\"magType\":\"mww\",\"type\":\"earthquake\",\"title\":\"M 6.6 - 215km SW of Tomatlan, Mexico\"},\"geometry\":{\"type\":\"Point\",\"coordinates\":[-106.9337,18.8239,10]},\"id\":\"us10004g4l\"},\r\n{\"type\":\"Feature\",\"properties\":{\"mag\":6.7,\"place\":\"52km SE of Shizunai, Japan\",\"time\":1452741933640,\"updated\":1466450357311,\"tz\":540,\"url\":\"http://earthquake.usgs.gov/earthquakes/eventpage/us10004ebx\",\"detail\":\"http://earthquake.usgs.gov/fdsnws/event/1/query?eventid=us10004ebx&format=geojson\",\"felt\":51,\"cdi\":5.8,\"mmi\":6.45,\"alert\":\"green\",\"status\":\"reviewed\",\"tsunami\":1,\"sig\":720,\"net\":\"us\",\"code\":\"10004ebx\",\"ids\":\",us10004ebx,gcmt20160114032534,pt16014050,at00o0xauk,gcmt20160114032533,\",\"sources\":\",us,gcmt,pt,at,gcmt,\",\"types\":\",associate,cap,dyfi,geoserve,impact-link,impact-text,losspager,moment-tensor,nearby-cities,origin,phase-data,shakemap,\",\"nst\":null,\"dmin\":0.281,\"rms\":0.98,\"gap\":22,\"magType\":\"mww\",\"type\":\"earthquake\",\"title\":\"M 6.7 - 52km SE of Shizunai, Japan\"},\"geometry\":{\"type\":\"Point\",\"coordinates\":[142.781,41.9723,46]},\"id\":\"us10004ebx\"},\r\n{\"type\":\"Feature\",\"properties\":{\"mag\":6.1,\"place\":\"12km WNW of Charagua, Bolivia\",\"time\":1452741928270,\"updated\":1463165886000,\"tz\":-240,\"url\":\"http://earthquake.usgs.gov/earthquakes/eventpage/us10004ebw\",\"detail\":\"http://earthquake.usgs.gov/fdsnws/event/1/query?eventid=us10004ebw&format=geojson\",\"felt\":3,\"cdi\":2.2,\"mmi\":2.21,\"alert\":\"green\",\"status\":\"reviewed\",\"tsunami\":0,\"sig\":573,\"net\":\"us\",\"code\":\"10004ebw\",\"ids\":\",us10004ebw,gcmt20160114032528,\",\"sources\":\",us,gcmt,\",\"types\":\",cap,dyfi,geoserve,impact-text,losspager,moment-tensor,nearby-cities,origin,phase-data,shakemap,tectonic-summary,\",\"nst\":null,\"dmin\":5.492,\"rms\":1.04,\"gap\":16,\"magType\":\"mww\",\"type\":\"earthquake\",\"title\":\"M 6.1 - 12km WNW of Charagua, Bolivia\"},\"geometry\":{\"type\":\"Point\",\"coordinates\":[-63.3288,-19.7597,582.56]},\"id\":\"us10004ebw\"},\r\n{\"type\":\"Feature\",\"properties\":{\"mag\":6.2,\"place\":\"74km NW of Rumoi, Japan\",\"time\":1452532083920,\"updated\":1463165873000,\"tz\":540,\"url\":\"http://earthquake.usgs.gov/earthquakes/eventpage/us10004djn\",\"detail\":\"http://earthquake.usgs.gov/fdsnws/event/1/query?eventid=us10004djn&format=geojson\",\"felt\":8,\"cdi\":3.4,\"mmi\":3.74,\"alert\":\"green\",\"status\":\"reviewed\",\"tsunami\":0,\"sig\":594,\"net\":\"us\",\"code\":\"10004djn\",\"ids\":\",us10004djn,gcmt20160111170803,\",\"sources\":\",us,gcmt,\",\"types\":\",cap,dyfi,geoserve,impact-text,losspager,moment-tensor,nearby-cities,origin,phase-data,shakemap,tectonic-summary,\",\"nst\":null,\"dmin\":1.139,\"rms\":0.96,\"gap\":33,\"magType\":\"mww\",\"type\":\"earthquake\",\"title\":\"M 6.2 - 74km NW of Rumoi, Japan\"},\"geometry\":{\"type\":\"Point\",\"coordinates\":[141.0867,44.4761,238.81]},\"id\":\"us10004djn\"},\r\n{\"type\":\"Feature\",\"properties\":{\"mag\":6.5,\"place\":\"227km SE of Sarangani, Philippines\",\"time\":1452530285900,\"updated\":1466450384901,\"tz\":480,\"url\":\"http://earthquake.usgs.gov/earthquakes/eventpage/us10004dj5\",\"detail\":\"http://earthquake.usgs.gov/fdsnws/event/1/query?eventid=us10004dj5&format=geojson\",\"felt\":1,\"cdi\":2.7,\"mmi\":7.5,\"alert\":\"green\",\"status\":\"reviewed\",\"tsunami\":1,\"sig\":650,\"net\":\"us\",\"code\":\"10004dj5\",\"ids\":\",gcmt20160111163807,at00o0srjp,pt16011050,us10004dj5,gcmt20160111163805,\",\"sources\":\",gcmt,at,pt,us,gcmt,\",\"types\":\",associate,cap,dyfi,geoserve,impact-link,impact-text,losspager,moment-tensor,nearby-cities,origin,phase-data,shakemap,tectonic-summary,\",\"nst\":null,\"dmin\":3.144,\"rms\":0.72,\"gap\":22,\"magType\":\"mww\",\"type\":\"earthquake\",\"title\":\"M 6.5 - 227km SE of Sarangani, Philippines\"},\"geometry\":{\"type\":\"Point\",\"coordinates\":[126.8621,3.8965,13]},\"id\":\"us10004dj5\"},\r\n{\"type\":\"Feature\",\"properties\":{\"mag\":6,\"place\":\"Pacific-Antarctic Ridge\",\"time\":1451986454620,\"updated\":1466450408406,\"tz\":-540,\"url\":\"http://earthquake.usgs.gov/earthquakes/eventpage/us10004bgk\",\"detail\":\"http://earthquake.usgs.gov/fdsnws/event/1/query?eventid=us10004bgk&format=geojson\",\"felt\":0,\"cdi\":1,\"mmi\":0,\"alert\":\"green\",\"status\":\"reviewed\",\"tsunami\":0,\"sig\":554,\"net\":\"us\",\"code\":\"10004bgk\",\"ids\":\",gcmt20160105093415,us10004bgk,gcmt20160105093414,\",\"sources\":\",gcmt,us,gcmt,\",\"types\":\",associate,cap,dyfi,geoserve,losspager,moment-tensor,nearby-cities,origin,phase-data,shakemap,\",\"nst\":null,\"dmin\":30.75,\"rms\":0.67,\"gap\":71,\"magType\":\"mww\",\"type\":\"earthquake\",\"title\":\"M 6.0 - Pacific-Antarctic Ridge\"},\"geometry\":{\"type\":\"Point\",\"coordinates\":[-136.2603,-54.2906,10]},\"id\":\"us10004bgk\"}],\"bbox\":[-153.4051,-54.2906,10,158.5463,59.6363,582.56]}";
        public static void main(String[] args) {
            // TODO Auto-generated method stub
            JSONObject rootObject = new JSONObject(str);
            JSONArray features = rootObject.getJSONArray("features");

             for(int i=0; i <features.length(); i++){
                 JSONObject jsonObjectForDetails = features.getJSONObject(i);

                 JSONObject jsonObjectForProperties = jsonObjectForDetails.getJSONObject("properties");


                 double magValue = jsonObjectForProperties.getDouble("mag");
                 String addressDetails = jsonObjectForProperties.getString("place");
                 long  dateDetails = jsonObjectForProperties.getLong("time");

                // dateObject = new Date(dateDetails);
                // long  dateToDisplay = simpleDateFormat.format(dateObject);
                // earthquakes.add(new Earthquake(magValue,addressDetails,dateDetails));

                 System.out.println(magValue + " " + addressDetails + " " + dateDetails);
             }
            System.out.println(rootObject.hashCode());
        }

    }