I get the following error
java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById (int)' on a null object reference
In the android studio Code
package com.example.lab_des_06.student;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.List;
public class viajes extends Fragment {
Cursor fila;
String concat;
String servidor_c;
String HttpURL;
ListView ViajesListView;
ProgressBar progressBar;
String HttpUrl = "http://158.97.121.14/smobil_app/WebService/ViajesList.php";
List<String> IdList = new ArrayList<>();
//private String d1;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null){
String d1 = getArguments().getString("username","0");
}
final String d1 = "laura";
// String d2 =extras.getString("pass");
// TextView binve = (TextView)getView().findViewById(R.id.nom2);
// binve.setText(d1);
//Variable de lista
ViajesListView = getView().findViewById(R.id.listview2);
progressBar = (ProgressBar)getView().findViewById(R.id.progressBar2);
new GetHttpResponse(getActivity()).execute();
//Al seleccionar la lista de viajes extrae la posicion de la id
ViajesListView.setOnItemClickListener(new AdapterView.OnItemClickListener()
{
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id){
//abre nueva pagina
Intent intent = new Intent(getActivity(),ViajesDescripcion.class);
intent.putExtra("username",d1);
// Envio de valor al darle clic del ListView con un intent
intent.putExtra("ListViewValue", IdList.get(position).toString());
try{
startActivity(intent);
}
catch (Exception e){
e.printStackTrace();
}
//Finishing current activity after open next activity.
//
// finish();
}
});
consulta();
// HttpURL = "http://"+concat+servidor_c+"ViajesList.php";
// Toast.ma
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final String d1 = "laura";
final TextView binve = (TextView)getView().findViewById(R.id.nom2);
binve.setText(d1);
/*
//Variable de lista
ViajesListView = (ListView)getView().findViewById(R.id.listview2);
progressBar = (ProgressBar)getView().findViewById(R.id.progressBar2);
// new GetHttpResponse(viajes.this).execute();
//Al seleccionar la lista de viajes extrae la posicion de la id
ViajesListView.setOnItemClickListener(new AdapterView.OnItemClickListener()
{
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//abre nueva pagina
Intent intent = new Intent(getActivity(),ViajesDescripcion.class);
intent.putExtra("username",d1);
// Envio de valor al darle clic del ListView con un intent
intent.putExtra("ListViewValue", IdList.get(position).toString());
try{
startActivity(intent);
}
catch (Exception e){
e.printStackTrace();
}
//Finishing current activity after open next activity.
//
// finish();
}
});
*/
consulta();
/// Toast.makeText(getContext(), "Envio"+d1, Toast.LENGTH_LONG).show();
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_listas, container, false);
}
private void consulta() {
DB consulta = new DB(getActivity().getApplicationContext(), null, null, 1);
SQLiteDatabase db = consulta.getWritableDatabase();
fila = db.rawQuery("SELECT ID, servidor,ip FROM datos WHERE id = (SELECT max(ID) FROM datos)", null);
if (fila.moveToFirst()) {
String id = fila.getString(0);
String servidor = fila.getString(1);
String ip = fila.getString(2);
concat =ip;
servidor_c =servidor;
}
}
private class GetHttpResponse extends AsyncTask<Void, Void, Void>{
public Context context;
String JSonResult;
List<Viaje> viajeList;
GetHttpResponse(Context context)
{
this.context = context;
}
@Override
protected void onPreExecute()
{
super.onPreExecute();
}
@Override
protected Void doInBackground(Void... arg0)
{
consulta();
// Passing HTTP URL to HttpServicesClass Class.
HttpServicesClass httpServicesClass = new HttpServicesClass("http://"+concat+"/"+servidor_c+"ViajesList.php");
//HttpServicesClass httpServicesClass = new HttpServicesClass(HttpUrl);
try
{
httpServicesClass.ExecutePostRequest();
if(httpServicesClass.getResponseCode() == 200)
{
JSonResult = httpServicesClass.getResponse();
if(JSonResult != null)
{
JSONArray jsonArray = null;
try {
jsonArray = new JSONArray(JSonResult);
JSONObject jsonObject;
Viaje viaje;
viajeList = new ArrayList<Viaje>();
for(int i=0; i<jsonArray.length(); i++)
{
viaje = new Viaje();
jsonObject = jsonArray.getJSONObject(i);
// Adding Student Id TO IdList Array.
IdList.add(jsonObject.getString("id").toString());
//Adding Student Name.
viaje.StudentName = jsonObject.getString("fecha_salida").toString();
viaje.Status = jsonObject.getString("status").toString();
viaje.Clave = jsonObject.getString("codigo").toString();
viajeList.add(viaje);
}
}
catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
else
{
Toast.makeText(context, httpServicesClass.getErrorMessage(), Toast.LENGTH_SHORT).show();
}
}
catch (Exception e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result)
{
progressBar.setVisibility(View.GONE);
ViajesListView.setVisibility(View.VISIBLE);
ListAdapterClass adapter = new ListAdapterClass(viajeList, context);
ViajesListView.setAdapter(adapter);
}
}}