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ListView cannot show a List retrieved from URL

I'm new to Android Studio. I'm trying to custom a Fragment automatically created by the IDE using the option create -> new Fragment (List). I'm not able to show the List retrieved from an http page, but if I manually add items to my list, the emulator let me see it. How can I solve this problem?
municipioFragment.java
package com.example.is2_app.ui.municipio;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.example.is2_app.R;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class municipioFragment extends Fragment {
// TODO: Customize parameters
private int mColumnCount = 1;
private List<News> lstNews;
private OnListFragmentInteractionListener mListener;
public municipioFragment() {
}
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
lstNews = new ArrayList<>();
getURL();
}
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container,
#Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_municipio_list, container, false);
// Set the adapter
if (view instanceof RecyclerView) {
Context context = view.getContext();
RecyclerView recyclerView = (RecyclerView) view;
if (mColumnCount <= 1) {
recyclerView.setLayoutManager(new LinearLayoutManager(context));
} else {
recyclerView.setLayoutManager(new GridLayoutManager(context, mColumnCount));
}
recyclerView.setAdapter(new MymunicipioRecyclerViewAdapter(lstNews, mListener));
}
return view;
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnListFragmentInteractionListener) {
mListener = (OnListFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnListFragmentInteractionListener");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p/>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnListFragmentInteractionListener {
// TODO: Update argument type and name
void onListFragmentInteraction(News item);
}
public void getURL() {
new Thread(new Runnable() {
#Override
public void run() {
final StringBuilder builder = new StringBuilder();
try {
Document doc = Jsoup.connect("http://www.comune.candida.av.it").get();
Element content = doc.getElementById("b370");
Elements subcontent = content.getElementsByTag("p");
String Text = null;
String Href = null;
int i = 0;
for (Element link : subcontent) {
Href = link.attr("href");
Text = link.text();
builder.append("\n").append(Text);
i = i + 1;
lstNews.add(new News(Integer.toString(i), Text));
}
} catch (IOException e) {
builder.append("Error: ").append(e.getMessage()).append("\n");
}
}
}).start();
}
}
MunicipioRecyclerViewAdapter.java
package com.example.is2_app.ui.municipio;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.recyclerview.widget.RecyclerView;
import com.example.is2_app.R;
import com.example.is2_app.ui.municipio.municipioFragment.OnListFragmentInteractionListener;
import java.util.List;
public class MymunicipioRecyclerViewAdapter extends RecyclerView.Adapter<MymunicipioRecyclerViewAdapter.ViewHolder> {
private final OnListFragmentInteractionListener mListener;
List<News> mData;
public MymunicipioRecyclerViewAdapter(List<News> mData, OnListFragmentInteractionListener listener) {
this.mData = mData;
this.mListener = listener;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.fragment_municipio, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(final ViewHolder holder, int position) {
//holder.mIdView.setText(mValues.get(position).id);
holder.mContentView.setText(mData.get(position).getId());
holder.mContentView.setText(mData.get(position).getContent());
}
#Override
public int getItemCount() {
return mData.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
public final View mView;
public final TextView mIdView;
public final TextView mContentView;
public ViewHolder(View view) {
super(view);
mView = view;
mIdView = (TextView) view.findViewById(R.id.item_number);
mContentView = (TextView) view.findViewById(R.id.content);
}
#Override
public String toString() {
return super.toString() + " '" + mContentView.getText() + "'";
}
}
}
fragment_municipio.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:id="#+id/item_number"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="#dimen/text_margin"
android:textAppearance="?attr/textAppearanceListItem" />
<TextView
android:id="#+id/content"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="#dimen/text_margin"
android:textAppearance="?attr/textAppearanceListItem" /> </LinearLayout>
fragment_municipio_list.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.recyclerview.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/list"
android:name="com.example.is2_app.ui.municipioFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp"
app:layoutManager="LinearLayoutManager"
tools:context=".ui.municipio.municipioFragment"
tools:listitem="#layout/fragment_municipio" />

So getUrl() is running in a Thread. In addition, getting the Document with JSoup is gonna need some time. This means that onCreateView will probably run before your lstNews is filled with the data you are scraping from the Document.
So you want to update your dataset; then, you want to notify your Adapter that your dataset changed.
Add this method to your Adapter
public void updateData(List<News> mData) {
this.mData = mData;
this.notifyDataSetChanged();
}
And after the for loop in getUrl(), you want to do the following:
runOnUiThread(new Runnable() {
#Override
public void run() {
recyclerViewAdapter.updateData(lstNews);
}
});
Where, recyclerViewAdapter is defined alongside recyclerView and initialized in the onCreateView.
So the following line:
recyclerView.setAdapter(new MymunicipioRecyclerViewAdapter(lstNews, mListener));
Will become:
recyclerViewAdapter = new MymunicipioRecyclerViewAdapter(lstNews, mListener);
recyclerView.setAdapter(recyclerViewAdapter);

Android load full image with recyclerview, cardview and volley from php mysql

The code below downloads images from a server and displays them in a recyclerview using php mysql and volley library as seen in the attached image. As of now when one clicks the image only toasts the image name. I want a user to be able to view the full image on click. Sorry to post all the code but its a desperate situation.
RecyclerView code
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerview1"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
</RelativeLayout>
CardView code
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="#+id/cardview1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
card_view:cardElevation="5dp"
card_view:contentPadding="5dp"
card_view:cardCornerRadius="5dp"
card_view:cardMaxElevation="5dp"
>
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#ECEFF1">
<com.android.volley.toolbox.NetworkImageView
android:id="#+id/VolleyImageView"
android:layout_width="150dp"
android:layout_height="100dp"
android:src="#mipmap/ic_launcher"
android:layout_marginTop="10dp"
android:layout_marginBottom="10dp"/>
<TextView
android:id="#+id/ImageNameTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginLeft="10dp"
android:layout_toEndOf="#+id/VolleyImageView"
android:layout_toRightOf="#+id/VolleyImageView"
android:text="JSon Image Name"
android:textColor="#000"
android:textSize="15dp" />
</RelativeLayout>
</androidx.cardview.widget.CardView>
MainActivity
package com.ny.fetchallimages;
import android.os.Bundle;
import org.json.JSONArray;
import java.util.ArrayList;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.android.volley.toolbox.Volley;
import java.util.List;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import org.json.JSONException;
import org.json.JSONObject;
public class MainActivity extends AppCompatActivity {
List<DataAdapter> ListOfdataAdapter;
RecyclerView recyclerView;
String HTTP_JSON_URL = "http://*************.php";
String Image_URL_JSON = "image_data";
String Image_Name_JSON = "image_tag";
JsonArrayRequest RequestOfJSonArray ;
RequestQueue requestQueue ;
View view ;
int RecyclerViewItemPosition ;
RecyclerView.LayoutManager layoutManagerOfrecyclerView;
RecyclerView.Adapter recyclerViewadapter;
ArrayList<String> ImageTitleNameArrayListForClick;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ImageTitleNameArrayListForClick = new ArrayList<>();
ListOfdataAdapter = new ArrayList<>();
recyclerView = (RecyclerView) findViewById(R.id.recyclerview1);
recyclerView.setHasFixedSize(true);
layoutManagerOfrecyclerView = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManagerOfrecyclerView);
JSON_HTTP_CALL();
// Implementing Click Listener on RecyclerView.
recyclerView.addOnItemTouchListener(new RecyclerView.OnItemTouchListener() {
GestureDetector gestureDetector = new GestureDetector(MainActivity.this, new GestureDetector.SimpleOnGestureListener() {
#Override public boolean onSingleTapUp(MotionEvent motionEvent) {
return true;
}
});
#Override
public boolean onInterceptTouchEvent(RecyclerView Recyclerview, MotionEvent motionEvent) {
view = Recyclerview.findChildViewUnder(motionEvent.getX(), motionEvent.getY());
if(view != null && gestureDetector.onTouchEvent(motionEvent)) {
//Getting RecyclerView Clicked Item value.
RecyclerViewItemPosition = Recyclerview.getChildAdapterPosition(view);
// Showing RecyclerView Clicked Item value using Toast.
Toast.makeText(MainActivity.this, ImageTitleNameArrayListForClick.get(RecyclerViewItemPosition), Toast.LENGTH_LONG).show();
}
return false;
}
#Override
public void onTouchEvent(RecyclerView Recyclerview, MotionEvent motionEvent) {
}
#Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
});
}
public void JSON_HTTP_CALL(){
RequestOfJSonArray = new JsonArrayRequest(HTTP_JSON_URL,
new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
ParseJSonResponse(response);
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
}
});
requestQueue = Volley.newRequestQueue(MainActivity.this);
requestQueue.add(RequestOfJSonArray);
}
public void ParseJSonResponse(JSONArray array){
for(int i = 0; i<array.length(); i++) {
DataAdapter GetDataAdapter2 = new DataAdapter();
JSONObject json = null;
try {
json = array.getJSONObject(i);
GetDataAdapter2.setImageTitle(json.getString(Image_Name_JSON));
// Adding image title name in array to display on RecyclerView click event.
ImageTitleNameArrayListForClick.add(json.getString(Image_Name_JSON));
GetDataAdapter2.setImageUrl(json.getString(Image_URL_JSON));
} catch (JSONException e) {
e.printStackTrace();
}
ListOfdataAdapter.add(GetDataAdapter2);
}
recyclerViewadapter = new RecyclerViewAdapter(ListOfdataAdapter, this);
recyclerView.setAdapter(recyclerViewadapter);
}
}
RecyclerViewAdapter
package com.ny.fetchallimages;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.android.volley.toolbox.NetworkImageView;
import java.util.List;
import com.android.volley.toolbox.ImageLoader;
import android.content.Context;
import android.view.LayoutInflater;
import androidx.recyclerview.widget.RecyclerView;
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder> {
Context context;
List<DataAdapter> dataAdapters;
ImageLoader imageLoader;
public RecyclerViewAdapter(List<DataAdapter> getDataAdapter, Context context){
super();
this.dataAdapters = getDataAdapter;
this.context = context;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.cardview, parent, false);
ViewHolder viewHolder = new ViewHolder(view);
return viewHolder;
}
#Override
public void onBindViewHolder(ViewHolder Viewholder, int position) {
DataAdapter dataAdapterOBJ = dataAdapters.get(position);
imageLoader = ImageAdapter.getInstance(context).getImageLoader();
imageLoader.get(dataAdapterOBJ.getImageUrl(),
ImageLoader.getImageListener(
Viewholder.VollyImageView,//Server Image
R.mipmap.ic_launcher,//Before loading server image the default showing image.
android.R.drawable.ic_dialog_alert //Error image if requested image dose not found on server.
)
);
Viewholder.VollyImageView.setImageUrl(dataAdapterOBJ.getImageUrl(), imageLoader);
Viewholder.ImageTitleTextView.setText(dataAdapterOBJ.getImageTitle());
}
#Override
public int getItemCount() {
return dataAdapters.size();
}
class ViewHolder extends RecyclerView.ViewHolder{
public TextView ImageTitleTextView;
public NetworkImageView VollyImageView ;
public ViewHolder(View itemView) {
super(itemView);
ImageTitleTextView = (TextView) itemView.findViewById(R.id.ImageNameTextView) ;
VollyImageView = (NetworkImageView) itemView.findViewById(R.id.VolleyImageView) ;
}
}
}
ImageAdapter
package com.ny.fetchallimages;
import android.graphics.Bitmap;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.RequestQueue;
import android.content.Context;;
import com.android.volley.toolbox.DiskBasedCache;
import com.android.volley.Cache;
import androidx.collection.LruCache;
import com.android.volley.Network;
import com.android.volley.toolbox.BasicNetwork;
import com.android.volley.toolbox.HurlStack;
public class ImageAdapter {
public static ImageAdapter imageAdapter;
public Network networkOBJ ;
public RequestQueue requestQueue1;
public ImageLoader Imageloader1;
public Cache cache1 ;
public static Context context1;
LruCache<String, Bitmap> LRUCACHE = new LruCache<String, Bitmap>(30);
private ImageAdapter(Context context) {
this.context1 = context;
this.requestQueue1 = RequestQueueFunction();
Imageloader1 = new ImageLoader(requestQueue1, new ImageLoader.ImageCache() {
#Override
public Bitmap getBitmap(String URL) {
return LRUCACHE.get(URL);
}
#Override
public void putBitmap(String url, Bitmap bitmap) {
LRUCACHE.put(url, bitmap);
}
});
}
public ImageLoader getImageLoader() {
return Imageloader1;
}
public static ImageAdapter getInstance(Context SynchronizedContext) {
if (imageAdapter == null) {
imageAdapter = new ImageAdapter(SynchronizedContext);
}
return imageAdapter;
}
public RequestQueue RequestQueueFunction() {
if (requestQueue1 == null) {
cache1 = new DiskBasedCache(context1.getCacheDir());
networkOBJ = new BasicNetwork(new HurlStack());
requestQueue1 = new RequestQueue(cache1, networkOBJ);
requestQueue1.start();
}
return requestQueue1;
}
}
DataAdapter
package com.ny.fetchallimages;
public class DataAdapter
{
public String ImageURL;
public String ImageTitle;
public String getImageUrl() {
return ImageURL;
}
public void setImageUrl(String imageServerUrl) {
this.ImageURL = imageServerUrl;
}
public String getImageTitle() {
return ImageTitle;
}
public void setImageTitle(String Imagetitlename) {
this.ImageTitle = Imagetitlename;
}
}

This worked by creating a new activity, then in on item click, get the item clicked position URL, send an intent to the activity with the image URL as extras. Get the image url from the intent in the activity then load the image.

How to maintain photo taken from camera on RecyclerView

It's my first time on StackOverFlow and Android Java language.
I have a doubt with my prototype app.
I'm going to explain it:
I have a adapter where i apply:
ReDatabaseAdapter
package prototype.es.applicationdb.adapter;
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v4.content.ContextCompat;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.List;
import prototype.es.applicationdb.R;
import prototype.es.applicationdb.utils.ImageGetter;
import prototype.es.applicationdb.utils.ReDatabaseEntry;
public class ReDatabaseAdapter extends RecyclerView.Adapter<ReDatabaseAdapter.ReDatabaseViewHolder> {
protected List<ReDatabaseEntry> mDB = null;
public ReDatabaseAdapter(List<ReDatabaseEntry> list){
mDB = new ArrayList<ReDatabaseEntry>(list);
}
#NonNull
#Override
public ReDatabaseViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int viewType) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.view_holder_layout,viewGroup,false);
return new ReDatabaseViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull ReDatabaseViewHolder reDatabaseViewHolder, int position) {
ReDatabaseEntry entry = mDB.get(position);
String name = entry.getName();
reDatabaseViewHolder.mName.setText(name);
int icon_id = ImageGetter.getIcon(name);
Context context = reDatabaseViewHolder.itemView.getContext();
reDatabaseViewHolder.mIcon.setImageDrawable(ContextCompat.getDrawable(
context,icon_id));
}
#Override
public int getItemCount() {
// total elements on JSON.
return mDB.size();
}
public class ReDatabaseViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
protected TextView mName = null;
protected ImageView mIcon = null;
public ReDatabaseViewHolder(#NonNull View itemView) {
super(itemView);
mName = itemView.findViewById(R.id.tv_char_name);
mIcon = itemView.findViewById(R.id.iv_char_icon);
mIcon.setOnClickListener(this);
}
#Override
public void onClick(View v) {
int viewId=v.getId();
if(viewId == mIcon.getId()) {
Intent intentToTakePicture = new Intent();
intentToTakePicture.setAction(MediaStore.ACTION_IMAGE_CAPTURE);
MainActivity contextAux = (MainActivity) mContext;
if (intentToTakePicture.resolveActivity(mContext.getPackageManager()) != null) {
contextAux.startActivityForResult(intentToTakePicture, 2);
}
}
}
}
}
In my MainActivity i have:
package prototype.es.applicationdb;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.widget.LinearLayout;
import org.json.JSONException;
import java.io.IOException;
import java.util.List;
import prototype.es.applicationdb.adapter.ReDatabaseAdapter;
import prototype.es.applicationdb.utils.ReDatabaseEntry;
import prototype.es.applicationdb.utils.ReJsonParser;
public class MainActivity extends AppCompatActivity {
protected List<ReDatabaseEntry> mList = null;
protected RecyclerView mRecyclerView = null;
protected ReDatabaseAdapter mAdapter = null;
protected LinearLayoutManager mManager = null;
protected ImageView mPhoto;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
try {
mList = ReJsonParser.parseJSONDatabase(getResources().openRawResource(R.raw.sw_db));
} catch(IOException e){
Log.e(getClass().getName(),e.getMessage());
} catch(JSONException e){
Log.e(getClass().getName(),e.getMessage());
}
mRecyclerView = findViewById(R.id.rv_database_viewer);
mAdapter = new ReDatabaseAdapter(mList);
mManager = new LinearLayoutManager(this);
mManager.setOrientation(LinearLayoutManager.HORIZONTAL);
mRecyclerView.setAdapter(mAdapter);
mRecyclerView.setLayoutManager(mManager);
}
#Override
protected void onActivityResult(int requestCode, int resultCode, #Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(requestCode==2 && resultCode == RESULT_OK){
//Get results from data
Bitmap img = (Bitmap) data.getExtras().get("data");
Bitmap bitmap = Bitmap.createScaledBitmap(img, 600, 800, false);
mPhoto = findViewById(R.id.iv_char_icon);
mPhoto.setImageBitmap(bitmap);
}
}
}
Getimage
package prototype.es.applicationdb.utils;
import prototype.es.applicationdb.R;
public class ImageGetter {
public static int getIcon(String name){
switch(name){
case "forest" :
return R.drawable.forest;
case "beach" :
return R.drawable.beach;
case "storms":
return R.drawable.storms;
case "design":
return R.drawable.design;
case "architecture" :
return R.drawable.architecture;
case "technologies":
return R.drawable.technologies;
case "music":
return R.drawable.music;
case "food":
return R.drawable.food;
case "animals":
return R.drawable.animals;
case "countries":
return R.drawable.countries;
case "transport":
return R.drawable.transport;
case "sports":
return R.drawable.sports;
case "fashion":
return R.drawable.fashion;
case "news":
return R.drawable.news;
default:
return R.drawable.defaultIcon;
}
}
}
Layout view_holder:
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fl_outer_card"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/card_border">
<ImageView
android:id="#+id/iv_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:layout_gravity="center_horizontal"/>
...
Layout activity_main:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<android.support.v7.widget.RecyclerView
android:layout_height="match_parent"
android:layout_width="match_parent"
android:id="#+id/rv_db_viewer"/>
</LinearLayout>
The problem is when i do long scrolling, my Recycler destroy my photo and appear the original picture. The original picture is recovered for adapter called from Parse JSON
How can i maintain my photo? I'm trying create a list where you click one ítem and you can attach a photo in this list and maintain the photo in the list.
I need your help, some idea will be grateful
Thanks in advance!

Hi you follow step by step this, tutorial.
I understand your problem, so please follow this, if you want to required
easy camera code then, click here
Step 1: Create DemoModel.java
import android.graphics.Bitmap;
import android.net.Uri;
public class DemoModel {
private String imagename = "";
private Bitmap imageBitmap= null;
public String getImagename() {
return imagename;
}
public void setImagename(String imagename) {
this.imagename = imagename;
}
public Bitmap getImageBitmap() {
return imageBitmap;
}
public void setImageBitmap(Bitmap imageBitmap) {
this.imageBitmap = imageBitmap;
}
}
Step 2: Create row_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<ImageView
android:id="#+id/ivImage"
android:layout_width="100dp"
android:layout_height="100dp"
android:src="#mipmap/ic_launcher_round" />
<TextView
android:id="#+id/tvText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_gravity="center_vertical"
android:gravity="center_vertical" />
</LinearLayout>
Step 3 : Create DemoAdapter.java
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;
public class DemoAdapter extends RecyclerView.Adapter<DemoAdapter.ViewHolder>
{
private String TAG = "GroupAdapter";
private Context mContext;
private LayoutInflater infalter;
private ArrayList<DemoModel> mDemoModelArrayList = new ArrayList<DemoModel>();
private View.OnClickListener mItemClickListener;
public DemoAdapter(Context context, View.OnClickListener itemClickListener, ArrayList<DemoModel> demoModelArrayList) {
this.infalter = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
this.mContext = context;
this.mDemoModelArrayList = demoModelArrayList;
this.mItemClickListener = itemClickListener;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(mContext).inflate(R.layout.row_item, parent, false);
ViewHolder viewHolder = new ViewHolder(view);
return viewHolder;
}
#Override
public void onBindViewHolder(DemoAdapter.ViewHolder holder, int position) {
holder.tvText.setText(mDemoModelArrayList.get(position).getImagename());
holder.ivImage.setImageBitmap(mDemoModelArrayList.get(position).getImageBitmap());
holder.ivImage.setTag(position);
holder.ivImage.setOnClickListener(mItemClickListener);
}
#Override
public int getItemCount() {
return mDemoModelArrayList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
private TextView tvText;
private ImageView ivImage;
public ViewHolder(View itemView) {
super(itemView);
tvText = (TextView) itemView.findViewById(R.id.tvText);
ivImage = (ImageView)itemView.findViewById(R.id.ivImage);
}
}
}
Step 4 : Write this code in Our MainActivity.java
import android.content.Intent;
import android.graphics.Bitmap;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
private RecyclerView rvrecylerView;
private DemoAdapter mDemoAdapter;
private ArrayList<DemoModel> mDemoModelArrayList = new ArrayList<DemoModel>();
int positionGl =0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setDummyData();
rvrecylerView = (RecyclerView)findViewById(R.id.rvrecylerView);
LinearLayoutManager mLinearLayout = new LinearLayoutManager(MainActivity.this, LinearLayoutManager.VERTICAL, false);
mLinearLayout.setSmoothScrollbarEnabled(true);
rvrecylerView.setLayoutManager(mLinearLayout);
rvrecylerView.setItemAnimator(new DefaultItemAnimator());
mDemoAdapter = new DemoAdapter(MainActivity.this,mItemClickListener,mDemoModelArrayList);
rvrecylerView.setAdapter(mDemoAdapter);
}
private void setDummyData() {
for (int i = 0; i < 50; i++) {
DemoModel tempDemoModel = new DemoModel();
tempDemoModel.setImagename("MyName "+i);
mDemoModelArrayList.add(tempDemoModel);
}
}
private View.OnClickListener mItemClickListener = new View.OnClickListener() {
#Override
public void onClick(View v) {
int position = (int)v.getTag();
positionGl = position;
openCamera(position);
}
};
private void openCamera(int postion) {
Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, 502);
}
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 502 && resultCode == RESULT_OK && data != null) {
Bitmap mphoto = (Bitmap) data.getExtras().get("data");
mDemoModelArrayList.get(positionGl).setImageBitmap(mphoto);
mDemoAdapter.notifyDataSetChanged();
}
}

why my recyclerview doesn't show data in fragment?

i have created the online wallpaper application and i used to activity for my app and i use volley and glide for my app but when i use bottom navigation drawer , activity is not useful .
after that i use fragment but now when i run application my recyclerview doesn't show anything
MainFragment.java:
package ir.zooding.wallpaper.activity;
import android.Manifest;
import android.app.ProgressDialog;
import android.content.pm.PackageManager;
import android.graphics.Color;
import android.os.Bundle;
import android.support.design.widget.Snackbar;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.Fragment;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import ir.zooding.wallpaper.R;
import ir.zooding.wallpaper.adapter.GalleryAdapter;
import ir.zooding.wallpaper.app.AppController;
import ir.zooding.wallpaper.model.Image;
import ir.zooding.wallpaper.receiver.ConnectivityReceiver;
public class MainFragment extends Fragment implements ConnectivityReceiver.ConnectivityReceiverListener {
RecyclerView recycler_view;
static final String url="";
ArrayList<Image> images;
GalleryAdapter mAdapter;
ProgressDialog pd;
View v;
public static MainFragment newInstance() {
MainFragment fragment = new MainFragment();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
v = inflater.inflate(R.layout.fragment_main, container, false);
Toolbar toolbar=(Toolbar)v.findViewById(R.id.toolbar);
((AppCompatActivity)getActivity()).setSupportActionBar(toolbar);
recycler_view=(RecyclerView) v.findViewById(R.id.recycler_view);
pd=new ProgressDialog(getActivity());
pd.setCancelable(false);
images=new ArrayList<>();
mAdapter=new GalleryAdapter(getActivity().getApplicationContext(),images);
RecyclerView.LayoutManager mLayoutManager=new GridLayoutManager(getActivity().getApplicationContext(),2);
recycler_view.setLayoutManager(mLayoutManager);
recycler_view.setAdapter(mAdapter);
Log.i("LOG:","stop 1");
ActivityCompat.requestPermissions(getActivity(),
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
1);
recycler_view.addOnItemTouchListener(new GalleryAdapter.RecyclerTouchListener(getActivity().getApplicationContext(),recycler_view, new GalleryAdapter.ClickListener() {
#Override
public void onClick(View view, int position) {
Bundle bundle=new Bundle();
bundle.putSerializable("images",images);
bundle.putInt("position",position);
//Log.i("LOG:",""+position);
// FragmentTransaction ft=getFragmentManager().beginTransaction();
android.app.FragmentTransaction ft=getActivity().getFragmentManager().beginTransaction();
SlideshowDialogFragment newFragment=SlideshowDialogFragment.newInstance();
newFragment.setArguments(bundle);
newFragment.show(ft,"slideshow");
}
#Override
public void onLongClick(View view, int position) {
}
}));
checkConnection();
fetchImages();
return inflater.inflate(R.layout.fragment_main, container, false);
}
#Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case 1: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted, yay! Do the
// contacts-related task you need to do.
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
Toast.makeText(getActivity(), "دسترسی به حافظه داخلی لغو شد!!!", Toast.LENGTH_LONG).show();
}
return;
}
// other 'case' lines to check for other
// permissions this app might request
}
}
public void fetchImages()
{
pd.setMessage("در حال بارگزاری ...");
pd.show();
StringRequest req = new StringRequest(url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.d("", response.toString());
pd.dismiss();
images.clear();
try {
JSONObject object = new JSONObject(response);
JSONArray dataArray = object.getJSONArray("data");
for (int i = 0; i < dataArray.length(); i++) {
JSONObject dataObject = dataArray.getJSONObject(i);
Image image = new Image();
image.setName_client(dataObject.getString("name_client"));
image.setName(dataObject.getString("name"));
// JSONObject url = object.getJSONObject("url");
image.setSmall(dataObject.getString("small"));
image.setOriginal(dataObject.getString("orginal"));
image.setTimestamp(dataObject.getString("timestamp"));
images.add(image);
}
} catch (JSONException e) {
e.printStackTrace();
}
Log.i("LOG:","stop 2");
mAdapter.notifyDataSetChanged();
Log.i("LOG:","stop 3");
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e("", "Error: " + error.getMessage());
pd.dismiss();
}
});
AppController.getmInstance().addToRequsetQueue(req);
}
// Method to manually check connection status
private void checkConnection() {
boolean isConnected = ConnectivityReceiver.isConnected();
showSnack(isConnected);
}
// Showing the status in Snackbar
private void showSnack(boolean isConnected) {
String message ="";
//View parentLayout = v.findViewById(android.R.id.content);
RelativeLayout parentLayout = (RelativeLayout)v.findViewById(R.id.mroot);
if (!isConnected) {
message = "اتصال شما به اینترنت برقرار نیست!";
Snackbar snackbar = Snackbar
.make(parentLayout, message, Snackbar.LENGTH_LONG)
.setAction("بررسی مجدد", new View.OnClickListener() {
#Override
public void onClick(View view) {
fetchImages();
checkConnection();
}
});
snackbar.setActionTextColor(Color.RED);
snackbar.setActionTextColor(Color.parseColor("#e62d3f"));
View sbView = snackbar.getView();
TextView textView = (TextView) sbView.findViewById(android.support.design.R.id.snackbar_text);
textView.setTextColor(Color.parseColor("#FFC107"));
snackbar.setDuration(8000);
snackbar.show();
}
}
#Override
public void onResume() {
super.onResume();
// register connection status listener
AppController.getmInstance().setConnectivityListener(this);
}
/**
* Callback will be triggered when there is change in
* network connection
*/
#Override
public void onNetworkConnectionChanged(boolean isConnected) {
showSnack(isConnected);
}
}
GalleryAdapter.java:
package ir.zooding.wallpaper.adapter;
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.GestureDetector;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import com.bumptech.glide.Glide;
import com.bumptech.glide.load.engine.DiskCacheStrategy;
import java.util.List;
import ir.zooding.wallpaper.R;
import ir.zooding.wallpaper.model.Image;
import static android.R.animator.fade_in;
public class GalleryAdapter extends RecyclerView.Adapter<GalleryAdapter.MyViewHolder> {
List<Image> images;
Context mContext;
public GalleryAdapter (Context context,List<Image> images){
this.images = images;
mContext = context;
}
#Override
public GalleryAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.gallery_thumbnail,parent,false);
return new MyViewHolder(view);
}
#Override
public void onBindViewHolder(GalleryAdapter.MyViewHolder holder, int position) {
Image image = images.get(position);
Glide.with(mContext).load(image.getSmall())
.thumbnail(0.5f)
.diskCacheStrategy(DiskCacheStrategy.ALL)
.placeholder(R.drawable.loading)
.fitCenter()
.into(holder.thumbnail);
}
#Override
public int getItemCount() {
return images.size();
}
public interface ClickListener{
void onClick (View view,int position);
void onLongClick (View view,int position);
}
public static class RecyclerTouchListener implements RecyclerView.OnItemTouchListener{
GalleryAdapter.ClickListener clickListener;
GestureDetector gestureDetector;
public RecyclerTouchListener(Context context,final RecyclerView recyclerView,final GalleryAdapter.ClickListener clickListener){
this.clickListener = clickListener;
gestureDetector = new GestureDetector(context,new GestureDetector.SimpleOnGestureListener(){
#Override
public boolean onSingleTapUp(MotionEvent e){
return true;
}
#Override
public void onLongPress(MotionEvent e){
View child = recyclerView.findChildViewUnder(e.getX(),e.getY());
if(child != null && clickListener != null){
clickListener.onLongClick(child,recyclerView.getChildPosition(child));
}
}
});
}
#Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
View child = rv.findChildViewUnder(e.getX(),e.getY());
if(child != null && clickListener != null&& gestureDetector.onTouchEvent(e)){
clickListener.onClick(child,rv.getChildPosition(child));
}
return false;
}
#Override
public void onTouchEvent(RecyclerView rv, MotionEvent e) {
}
#Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
}
public class MyViewHolder extends RecyclerView.ViewHolder{
ImageView thumbnail;
public MyViewHolder(View view) {
super(view);
thumbnail =(ImageView) view.findViewById(R.id.thumbnail);
}
}
}
MainActivity.java:
package ir.zooding.wallpaper.activity;
import android.support.annotation.NonNull;
import android.support.design.widget.BottomNavigationView;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.view.MenuItem;
import ir.adad.client.Adad;
import ir.zooding.wallpaper.R;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Adad.initialize(getApplicationContext());
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
BottomNavigationView bottomNavigationView = (BottomNavigationView)
findViewById(R.id.navigation);
bottomNavigationView.setOnNavigationItemSelectedListener
(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment selectedFragment = null;
switch (item.getItemId()) {
case R.id.action_item1:
selectedFragment = MainFragment.newInstance();
break;
case R.id.action_item2:
selectedFragment = CategoryFragment.newInstance();
break;
case R.id.action_item3:
selectedFragment = InfoFragment.newInstance();
break;
}
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.frame_layout, selectedFragment);
transaction.commit();
return true;
}
});
//Manually displaying the first fragment - one time only
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.frame_layout, MainFragment.newInstance());
transaction.commit();
//Used to select an item programmatically
//bottomNavigationView.getMenu().getItem(2).setChecked(true);
}
}
fragment_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<RelativeLayout
android:id="#+id/mroot"
android:layout_width="match_parent"
android:layout_height="match_parent">
</RelativeLayout>
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
/>
</android.support.design.widget.AppBarLayout>
<include
android:id="#+id/include"
layout="#layout/content_main"/>
content_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingTop="?attr/actionBarSize">
<android.support.v7.widget.RecyclerView
android:id="#+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:scrollbars="vertical"/>

There are Contexts considerations you need to make throught your code. You may be using the wrong Contexts example very big Contexts. For example from what I can see fast one of it is this line in MainFragment.java:
mAdapter=new GalleryAdapter(getActivity().getApplicationContext(),images);
You have passed the application context while you need just Context from Activity. So change that to:
mAdapter=new GalleryAdapter(getActivity(),images); // remove the method getApplicationContext
Try doing that if it will work or else lets try finding more code that may bring a problem.

RecyclerView Issue

MainActivity.java
its my main java class
package com.example.shikhu.newpractice;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
Button button;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(MainActivity.this,DisplayList.class));
}
});
}
}
DisplayList.java
package com.example.shikhu.newpractice;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
public class DisplayList extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dsiplay_list);
BackgroundTask backgroundTask = new BackgroundTask(DisplayList.this);
backgroundTask.execute();
}
}
BackgroundTask.java
package com.example.shikhu.newpractice;
import android.app.Activity;
import android.content.Context;
import android.os.AsyncTask;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
public class BackgroundTask extends AsyncTask<Void,Fruit,Void> {
String json_string = "http://192.168.1.18:8081/fruitinfo/get_fruit_details.php";
Context ctx;
Activity activity;
RecyclerView recyclerView;
RecyclerView.Adapter adapter;
RecyclerView.LayoutManager layoutManager;
ArrayList<Fruit> arrayList = new ArrayList<>();
public BackgroundTask(Context ctx)
{
this.ctx=ctx;
activity = (Activity)ctx;
}
#Override
protected void onPreExecute() {
recyclerView = (RecyclerView)activity.findViewById(R.id.recyclerview);
layoutManager = new LinearLayoutManager(ctx);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setHasFixedSize(true);
adapter = new RecyclerAdapter(arrayList);
recyclerView.setAdapter(adapter);
}
#Override
protected Void doInBackground(Void... params) {
try{
URL url = new URL(json_string);
HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder stringBuilder = new StringBuilder();
String line;
while((line=bufferedReader.readLine())!=null)
{
stringBuilder.append(line + "\n");
}
httpURLConnection.disconnect();
String json_string = stringBuilder.toString().trim();
JSONObject jsonObject = new JSONObject(json_string);
JSONArray jsonArray = jsonObject.getJSONArray("server_response");
int count = 0;
while (count<jsonArray.length())
{
JSONObject JO = jsonArray.getJSONObject(count);
count++;
Fruit fruit = new Fruit(JO.getString("name"),JO.getInt("calories"),JO.getDouble("fat"));
publishProgress(fruit);
}
Log.d("JSON STRING",json_string);
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onProgressUpdate(Fruit... values) {
arrayList.add(values[0]);
adapter.notifyDataSetChanged();
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
}
}
RecyclerAdapter.java
package com.example.shikhu.newpractice;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.ArrayList;
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.RecyclerViewHolder> {
private static final int TYPE_HEAD = 0;
private static final int TYPE_LIST = 1;
ArrayList<Fruit> arrayList = new ArrayList<>();
public RecyclerAdapter(ArrayList<Fruit> arrayList)
{
this.arrayList =arrayList;
}
#Override
public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == TYPE_HEAD)
{
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.header_layout,parent,false);
RecyclerViewHolder recyclerViewHolder = new RecyclerViewHolder(view,viewType);
return recyclerViewHolder;
}
else if (viewType == TYPE_LIST)
{
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_layout,parent,false);
RecyclerViewHolder recyclerViewHolder = new RecyclerViewHolder(view,viewType);
return recyclerViewHolder;
}
return null;
}
#Override
public void onBindViewHolder(RecyclerViewHolder holder, int position) {
if (holder.viewType == TYPE_LIST) {
Fruit fruit = arrayList.get(position);
holder.Name.setText(fruit.getName());
holder.Calories.setText(Integer.toString(fruit.getCalories()));
holder.Fat.setText(Double.toString(fruit.getFat()));
}
}
#Override
public int getItemCount() {
return arrayList.size();
}
public static class RecyclerViewHolder extends RecyclerView.ViewHolder
{
TextView Name,Calories,Fat;
int viewType;
public RecyclerViewHolder(View v,int viewType)
{
super(v);
if (viewType == TYPE_LIST) {
Name = (TextView) v.findViewById(R.id.name);
Calories = (TextView) v.findViewById(R.id.calories);
Fat = (TextView) v.findViewById(R.id.fat);
this.viewType = TYPE_LIST;
}else if (viewType == TYPE_HEAD)
{
this.viewType = TYPE_HEAD;
}
}
public int getItemViewType(int position)
{
if (position==0)
return TYPE_HEAD;
return TYPE_LIST;
}
}
}
Fruit.java
package com.example.shikhu.newpractice;
public class Fruit {
private String name;
private int calories;
private Double fat;
public Fruit(String name,int calories,Double fat)
{
this.setName(name);
this.setCalories(calories);
this.setFat(fat);
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name=name;
}
public int getCalories()
{
return calories;
}
public void setCalories(int calories)
{
this.calories=calories;
}
public Double getFat()
{
return fat;
}
public void setFat(Double fat)
{
this.fat=fat;
}
}
Row_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
android:layout_height="75dp"
android:layout_marginRight="15dp"
android:layout_marginLeft="15dp"
android:weightSum="1">
<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:textStyle="bold"
android:textSize="20dp"
android:text="Name"
android:id="#+id/name"
android:layout_weight="0.39" />
<TextView
android:layout_width="79dp"
android:layout_height="match_parent"
android:text="Calorie"
android:gravity="center_vertical"
android:textSize="20dp"
android:textStyle="bold"
android:id="#+id/calories"
android:layout_marginLeft="40dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="Fat"
android:gravity="center_vertical"
android:textSize="20dp"
android:textStyle="bold"
android:id="#+id/fat"
android:layout_weight="0.15"
android:layout_marginLeft="60dp" />
</LinearLayout>
Header_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
android:layout_height="65dp"
android:background="?attr/colorPrimary">
<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:textStyle="bold"
android:textSize="20dp"
android:text="Name"
android:id="#+id/name1"
android:layout_weight="0.20"
android:textColor="#ffffff"
android:layout_marginLeft="10dp" />
<TextView
android:layout_width="79dp"
android:layout_height="match_parent"
android:text="Calorie"
android:gravity="center_vertical"
android:textSize="20dp"
android:textStyle="bold"
android:id="#+id/calories1"
android:layout_marginLeft="10dp"
android:textColor="#ffffff"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="Fat"
android:gravity="center_vertical"
android:textSize="20dp"
android:textStyle="bold"
android:id="#+id/fat1"
android:layout_weight="0.15"
android:layout_marginLeft="60dp"
android:textColor="#ffffff"/>
</LinearLayout>
activity_display_list.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".DisplayList">
<android.support.v7.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/recyclerview"></android.support.v7.widget.RecyclerView>
</RelativeLayout>
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.example.shikhu.newpractice.MainActivity">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Display List"
android:id="#+id/button"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true" />
</RelativeLayout>
My Output
i dont know why it is showing text of textview rather the data fetched from database
enter image description here
PhpScript
<?php
$host = "localhost";
$user = "root";
$pass = "";
$db = "fruit";
$con = mysqli_connect($host,$user,$pass,$db);
$query= "select * from fruit_details;";
$result = mysqli_query($con,$query);
$response = array();
while($row = mysqli_fetch_array($result))
{
array_push($response,array('name'=>$row[0],'calories'=>$row[1],'fat'=>$row[2 ]));
}
mysqli_close($con);
echo json_encode(array('server_response'=>$response));
?>

Your Adapter always return TYPE_HEAD i think this is wrong.
#Override
public int getItemViewType(int position) {
if (position == 0) {
return TYPE_HEAD;
} else {
return TYPE_LIST;
}
}

BackgroundTask.Java
package com.example.shikhu.newpractice;
import android.app.Activity;
import android.content.Context;
import android.os.AsyncTask;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
public class BackgroundTask extends AsyncTask<Void,Fruit,Void> {
String json_string = "http://127.0.0.1:8081/fruitinfo/get_fruit_details.php";
Context ctx;
Activity activity;
RecyclerView recyclerView;
RecyclerView.Adapter adapter;
RecyclerView.LayoutManager layoutManager;
ArrayList<Fruit> arrayList = new ArrayList<>();
public BackgroundTask(Context ctx)
{
this.ctx=ctx;
activity = (Activity)ctx;
}
#Override
protected void onPreExecute() {
recyclerView = (RecyclerView)activity.findViewById(R.id.recyclerview);
layoutManager = new LinearLayoutManager(ctx);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setHasFixedSize(true);
adapter = new RecyclerAdapter(arrayList);
recyclerView.setAdapter(adapter);
}
#Override
protected Void doInBackground(Void... params) {
try{
URL url = new URL(json_string);
HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder stringBuilder = new StringBuilder();
String line;
while((line=bufferedReader.readLine())!=null)
{
stringBuilder.append(line + "\n");
}
httpURLConnection.disconnect();
String json_string = stringBuilder.toString().trim();
JSONObject jsonObject = new JSONObject(json_string);
JSONArray jsonArray = jsonObject.getJSONArray("server_response");
int count = 0;
while (count<jsonArray.length())
{
JSONObject JO = jsonArray.getJSONObject(count);
count++;
Fruit fruit = new Fruit(JO.getString("name"),JO.getInt("calorie"),JO.getDouble("fat"));
publishProgress(fruit);
}
Log.d("JSON STRING",json_string);
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onProgressUpdate(Fruit... values) {
arrayList.add(values[0]);
adapter.notifyDataSetChanged();
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
}
}
RecyclerAdapter.java
package com.example.shikhu.newpractice;
import android.support.annotation.IdRes;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.ArrayList;
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.RecyclerViewHolder> {
private static final int TYPE_HEAD = 0;
private static final int TYPE_LIST = 1;
ArrayList<Fruit> arrayList = new ArrayList<>();
public RecyclerAdapter(ArrayList<Fruit> arrayList)
{
this.arrayList =arrayList;
}
#Override
public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == TYPE_HEAD)
{
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.header_layout,parent,false);
RecyclerViewHolder recyclerViewHolder = new RecyclerViewHolder(view,viewType);
return recyclerViewHolder;
}
else if (viewType == TYPE_LIST)
{
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_layout,parent,false);
RecyclerViewHolder recyclerViewHolder = new RecyclerViewHolder(view,viewType);
return recyclerViewHolder;
}
return null;
}
#Override
public void onBindViewHolder(RecyclerViewHolder holder, int position) {
if (holder.viewType == TYPE_LIST) {
Fruit fruit = arrayList.get(position-1);
holder.Name.setText(fruit.getName());
holder.Calories.setText(Integer.toString(fruit.getCalories()));
holder.Fat.setText(Double.toString(fruit.getFat()));
}
}
#Override
public int getItemCount() {
return arrayList.size()+1;
}
public static class RecyclerViewHolder extends RecyclerView.ViewHolder
{
TextView Name,Calories,Fat;
int viewType;
public RecyclerViewHolder(View v,int viewType)
{
super(v);
if (viewType == TYPE_LIST) {
Name = (TextView) v.findViewById(R.id.name);
Calories = (TextView) v.findViewById(R.id.calories);
Fat = (TextView) v.findViewById(R.id.fat);
this.viewType = TYPE_LIST;
}else if (viewType == TYPE_HEAD)
{
this.viewType = TYPE_HEAD;
}
}
}
#Override
public int getItemViewType(int position) {
if (position==0)
return TYPE_HEAD;
else
return TYPE_LIST;
}
}

I think you are not managing views for header in your view holder and from bind view holder it is everytime getting only header view in return; SO just debug your code and let me know that are you getting TYPE_LIST data view or not. Also make references for header view in View holder and set text to it also.

I found your problem.
Your method getItemViewType is inside your ViewHolder class. It needs to be moved to be inside your adapter class. Right now, since your adapter has no getItemViewType method, it assumes all view types are 0 (HEADER), and so nothing is being bound.
Move this method to your adapter class and all will work :)
Edit
Another option which should work for you is to stop using viewTypes all together. Since you're using the same viewHolder anyway, when you bind the view, instead of checking the viewType, check the position:
#Override
public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_layout,parent,false);
RecyclerViewHolder recyclerViewHolder = new RecyclerViewHolder(view, TYPE_LIST);
return recyclerViewHolder;
}
#Override
public void onBindViewHolder(RecyclerViewHolder holder, int position) {
if (position > 0) {
Fruit fruit = arrayList.get(position-1);
holder.Name.setText(fruit.getName());
holder.Calories.setText(Integer.toString(fruit.getCalories()));
holder.Fat.setText(Double.toString(fruit.getFat()));
} else {
holder.Name.setText("Name");
holder.Calories.setText("Calories");
holder.Fat.setText("Fat");
}
}
So now, all your view types will be of type list. This is fine, because the layout is basically identical, only the values of the TextViews changes. Instead of using viewType, simply use the position. If the position is 0, set the header fields, otherwise, use the Fruit data.
I know this is not the solution you wanted - I can't seem to find why the viewType implementation doesn't work, however, this solution should give you the result you wanted.
Hope this helps!