when I run my project then error show in log cat which is not understandable for me please anyone can help me what is the meaning of these errors mean what mistakes I am making in my codes. Even I download other projects from google, on the running same log cat is showing please help.
LogCat is here:-
02-03 12:09:05.115 7614-7614/com.example.administrator.mainpage E/GMPM: GoogleService failed to initialize, status: 10, Missing an expected resource: 'R.string.google_app_id' for initializing Google services. Possible causes are missing google-services.json or com.google.gms.google-services gradle plugin.
02-03 12:09:05.115 7614-7614/com.example.administrator.mainpage E/GMPM: Scheduler not set. Not logging error/warn.
02-03 12:09:05.240 7614-7639/com.example.administrator.mainpage E/GMPM: Uploading is not possible. App measurement disabled
02-03 12:09:06.371 7614-7689/com.example.administrator.mainpage E/GED: Failed to get GED Log Buf, err(0)
02-03 12:09:06.471 7614-7614/com.example.administrator.mainpage E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.administrator.mainpage, PID: 7614
java.lang.NullPointerException: Attempt to invoke interface method 'int java.util.List.size()' on a null object reference
at android.widget.ArrayAdapter.getCount(ArrayAdapter.java:330)
at android.widget.ListView.setAdapter(ListView.java:499)
at com.example.administrator.mainpage.MainActivity$JSONTask.onPostExecute(MainActivity.java:56)
at com.example.administrator.mainpage.MainActivity$JSONTask.onPostExecute(MainActivity.java:41)
at android.os.AsyncTask.finish(AsyncTask.java:636)
at android.os.AsyncTask.access$500(AsyncTask.java:177)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:653)
at android.os.Handler.dispatchMessage(Handler.java:111)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5649)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:959)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:754)
This is code:-
public class MainActivity extends AppCompatActivity {
ListView lvCity;
private static String url="14.140.200.186/Hospital/get_city.php";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.arjuncontent_main);
new JSONTask().execute(url);
}
public class JSONTask extends AsyncTask<String,String, List<CityModel>>{
private final ProgressDialog dialog = new ProgressDialog(MainActivity.this);
@Override
protected void onPreExecute() {
super.onPreExecute();
dialog.setMessage("Downloading Cities...");
dialog.show();
}
@Override
protected void onPostExecute( List<CityModel> result) {
super.onPostExecute(result);
CityAdapter adapter=new CityAdapter(getApplicationContext(),R.layout.city_single_row,result);
lvCity = (ListView) findViewById(R.id.lvCity);
lvCity.setAdapter(adapter);
}
public class CityAdapter extends ArrayAdapter {
private List<CityModel> cityModelList;
private int resource;
private LayoutInflater inflater;
public CityAdapter(Context context, int resource, List<CityModel> objects) {
super(context, resource, objects);
cityModelList=objects;
this.resource=resource;
inflater= (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView==null)
convertView=inflater.inflate(resource,null);
TextView cityname;
TextView cityid;
cityid= (TextView) convertView.findViewById(R.id.cityid);
cityid.setText(cityModelList.get(position).getCity_id());
cityname= (TextView)convertView.findViewById(R.id.cityname);
cityname.setText(cityModelList.get(position).getCity_name());
return convertView;
}
}
@Override
protected List<CityModel> doInBackground(String... params) {
HttpURLConnection connection = null;
BufferedReader reader = null;
try {
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
String finalJson=buffer.toString();
JSONObject parentObject=new JSONObject(finalJson);
JSONArray parentArray=parentObject.getJSONArray("Cities");
List<CityModel>cityModelList=new ArrayList<>();
for (int i=0; i<parentArray.length(); i++){
JSONObject finalObject = parentArray.getJSONObject(i);
CityModel cityModel=new CityModel();
cityModel.setCity_name(finalObject.getString("city_name"));
cityModel.setCity_id(finalObject.getString("city_id"));
cityModelList.add(cityModel);
}
return cityModelList;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
} finally {
if (connection != null)
connection.disconnect();
;
try {
if (reader != null)
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
}
`
