I'm trying to get the data from json using url. There is no problem with json.
This is the json url
I'm getting null point exception error. I guess the problem is with my getData() function.
I tried with hard coded values, it worked perfectly.
public class search_fragment extends Fragment {
String url;
String[] salonName;
String[] salonType;
String[] city;
String[] image;
//String[] salonName ={"A salon", "B salon"};
//String[] salonType = {"Female", "Female"};
//String[] city = {"Colombo", "KAndy"};
ListView lst;
View view;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable
ViewGroup container, @Nullable Bundle savedInstanceState) {
view = inflater.inflate(R.layout.fragment_search, container, false);
lst = view.findViewById(R.id.salonList);
ListViewAdapter listViewAdapter = new ListViewAdapter(getActivity(),
salonName, salonType, city, image);
lst.setAdapter(listViewAdapter);
return view;
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getData();
}
void getData(){
RequestQueue requestQueue = Volley.newRequestQueue(getContext());
url = "https://newswiftsalon.000webhostapp.com/Salon.php";
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(url, new
Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
int length = response.length();
salonName = new String[length];
salonType = new String[length];
city = new String[length];
image = new String[length];
for(int i = 0; i< response.length(); i++){
try{
JSONObject salons = response.getJSONObject(i);
salonName[i] = salons.getString("salonName");
salonType[i] = salons.getString("salonType");
city[i] = salons.getString("City");
image[i] = salons.getString("image");
} catch (JSONException e){
e.printStackTrace();
}
}
Log.d("salon Name", salonName[1]);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
});
requestQueue.add(jsonArrayRequest);
}
}
Adapter class
public class ListViewAdapter extends ArrayAdapter<String> {
private String[] salonName;
private String[] salonType;
private String[] city;
private String[] image;
private Activity context;
public ListViewAdapter(Activity context , String[] salonName, String[]
salonType, String[] city, String[] image ){
super(context, R.layout.salon_list, salonName);
this.context = context;
this.salonName = salonName;
this.salonType = salonType;
this.city = city;
this.image = image;
}
@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull
ViewGroup parent) {
View r = convertView;
ViewHolder viewHolder = null;
if(r==null){
LayoutInflater layoutInflater = context.getLayoutInflater();
r=layoutInflater.inflate(R.layout.salon_list, null, true);
viewHolder=new ViewHolder(r);
r.setTag(viewHolder);
}
else {
viewHolder =(ViewHolder) r.getTag();
}
viewHolder.txtType.setText(salonType[position]);
viewHolder.txtSalonName.setText(salonName[position]);
viewHolder.txtCity.setText(city[position]);
return r;
}
class ViewHolder
{
TextView txtType;
TextView txtSalonName;
TextView txtCity;
ImageView imageview;
ViewHolder(View v){
txtCity = v.findViewById(R.id.txt_city);
txtSalonName = v.findViewById(R.id.txt_salon_name);
txtType = v.findViewById(R.id.txt_type);
imageview = v.findViewById(R.id.img_salon);
}
}
}
This is the error
E/AndroidRuntime: FATAL EXCEPTION: main
Process: lk.nibm.swiftsalon, PID: 3485
java.lang.NullPointerException
at java.util.Objects.requireNonNull(Objects.java:203)
at java.util.Arrays$ArrayList.<init>(Arrays.java:3738)
at java.util.Arrays.asList(Arrays.java:3725)
at android.widget.ArrayAdapter.<init>(ArrayAdapter.java:168)
at lk.nibm.swiftsalon.ListViewAdapter.<init>(ListViewAdapter.java:30)
at lk.nibm.swiftsalon.search_fragment.onCreateView(search_fragment.java:48)
at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2600)
at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:881)
at androidx.fragment.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManagerImpl.java:1238)
at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:1303)
at androidx.fragment.app.BackStackRecord.executeOps(BackStackRecord.java:439)
at androidx.fragment.app.FragmentManagerImpl.executeOps(FragmentManagerImpl.java:2079)
at androidx.fragment.app.FragmentManagerImpl.executeOpsTogether(FragmentManagerImpl.java:1869)
at androidx.fragment.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManagerImpl.java:1824)
at androidx.fragment.app.FragmentManagerImpl.execPendingActions(FragmentManagerImpl.java:1727)
at androidx.fragment.app.FragmentManagerImpl$2.run(FragmentManagerImpl.java:150)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7356)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
Try this:
void getData(){
RequestQueue requestQueue = Volley.newRequestQueue(getContext());
url = "https://newswiftsalon.000webhostapp.com/Salon.php";
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(url, new
Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
int length = response.length();
salonName = new String[length];
salonType = new String[length];
city = new String[length];
image = new String[length];
for(int i = 0; i< response.length(); i++){
try{
JSONObject salons = response.getJSONObject(i);
salonName[i] = salons.getString("salonName");
salonType[i] = salons.getString("salonType");
city[i] = salons.getString("City");
image[i] = salons.getString("image");
} catch (JSONException e){
e.printStackTrace();
}
}
Log.d("salon Name", salonName[1]);
ListViewAdapter listViewAdapter = new ListViewAdapter(getActivity(),
salonName, salonType, city, image);
lst.setAdapter(listViewAdapter);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
});
requestQueue.add(jsonArrayRequest);
}
remove your getData() method call from onCreate and put it in onCreateView like this:
lst = view.findViewById(R.id.salonList);
getData();