i am using volley to make REST API requests to tmdb database for loading information about movies. The recycler view should display thumbnail image posters. But it is not displaying anything. i am using picasso library to load images. the image links are constructed fine, which i have checked with log statement
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:id="@+id/activity_main"
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.android.moviesapp.MainActivity">
<android.support.v7.widget.RecyclerView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/movierecyclerview">
</android.support.v7.widget.RecyclerView>
</RelativeLayout>
list_item_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/movie_poster_cardview">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/movie_poster_imageview"/>
</android.support.v7.widget.CardView>
MainActivity
package com.example.android.moviesapp;
import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.squareup.picasso.Callback;
import com.squareup.picasso.Picasso;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
public class MainActivity extends AppCompatActivity {
private ArrayList<HashMap<String, String>> movies = new ArrayList<>();
private ArrayList<String> moviePosters = new ArrayList<>();
final static String POSTER_PATH = "poster_path";
final static String TITLE = "title";
final static String VOTE_COUNT = "vote_count";
final static String VOTE_AVERAGE = "vote_average";
final static String OVERVIEW = "overview";
final static String RELEASE_DATE ="release_date";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final MoviesAdapter adapter = new MoviesAdapter(getApplicationContext(), moviePosters);
RecyclerView moviesRecyclerView = (RecyclerView) findViewById(R.id.movierecyclerview);
moviesRecyclerView.setAdapter(adapter);
moviesRecyclerView.setLayoutManager(new GridLayoutManager(getApplicationContext(), 2));
try {
final String BASE_URL =
"https://api.themoviedb.org/3/movie/";
final String movieOrder = "popular";
final String APPID = /* API KEY HERE */;
Uri builtUri = Uri.parse(BASE_URL).buildUpon().appendPath(movieOrder).appendQueryParameter("api_key",APPID).build();
URL url = new URL(builtUri.toString());
JsonObjectRequest movieRequest = new JsonObjectRequest(Request.Method.GET, url.toString(), null, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
try {
JSONArray results = response.getJSONArray("results");
Log.d ("DEBUG", response.toString());
for (int i = 0; i < results.length(); i++) {
JSONObject movieJSON = results.getJSONObject(i);
HashMap<String, String> movie = new HashMap<>();
movie.put(POSTER_PATH,movieJSON.getString(POSTER_PATH));
movie.put(TITLE,movieJSON.getString(TITLE));
movie.put(VOTE_COUNT,movieJSON.getString(VOTE_COUNT));
movie.put(VOTE_AVERAGE, movieJSON.getString(VOTE_AVERAGE));
movie.put(OVERVIEW, movieJSON.getString(OVERVIEW));
movie.put(RELEASE_DATE, movieJSON.getString(RELEASE_DATE));
movies.add(movie);
}
}
catch (JSONException e) {
Log.d ("DEBUG", "JSON exception");
}
for (HashMap<String, String> movie:movies) {
moviePosters.add(movie.get(POSTER_PATH));
adapter.notifyDataSetChanged();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.d ("DEBUG","Network Error");
}
});
RequestQueue mRequestQueue = MovieDataLoader.getSingletonInstance(this.getApplicationContext()).getRequestQueue();
mRequestQueue.add(movieRequest);
}
catch (MalformedURLException e) {
Log.d("DEBUG", "url not formed correctly");
}
}
public class MoviesAdapter extends RecyclerView.Adapter<MoviesAdapter.MoviesViewHolder> {
private ArrayList<String> movies;
private Context mContext;
public class MoviesViewHolder extends RecyclerView.ViewHolder {
public ImageView mImageView;
public MoviesViewHolder (View itemView) {
super(itemView);
mImageView = (ImageView) itemView.findViewById(R.id.movie_poster_imageview);
}
}
public MoviesAdapter(Context context, ArrayList<String> movies) {
this.movies = movies;
mContext = context;
}
@Override
public MoviesViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View moviesView = inflater.inflate(R.layout.list_item_layout,parent,false);
return new MoviesViewHolder(moviesView);
}
@Override
public int getItemCount() {
return movies.size();
}
@Override
public void onBindViewHolder(MoviesViewHolder holder, int position) {
String moviePosterPath = movies.get(position);
final String BASE_URL = " http://image.tmdb.org/t/p/";
final String IMAGE_SIZE = "w185";
Uri posterPath = Uri.parse(BASE_URL).buildUpon().appendPath(IMAGE_SIZE).appendEncodedPath(moviePosterPath).build();
Log.d("DEBUG",posterPath.toString());
picasso.with(mContext).load(posterPath.toString()).into(holder.mImageView);
}
}
}
MovieDataLoader
package com.example.android.moviesapp;
import android.content.Context;
import android.graphics.Bitmap;
import android.util.LruCache;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.NetworkImageView;
import com.android.volley.toolbox.Volley;
public class MovieDataLoader {
private static MovieDataLoader mSingletonInstance;
private RequestQueue mRequestQueue;
private static Context mCtx;
private MovieDataLoader(Context ctx) {
mCtx = ctx;
mRequestQueue = getRequestQueue();
}
public static synchronized MovieDataLoader getSingletonInstance(Context ctx) {
if (mSingletonInstance == null) {
mSingletonInstance = new MovieDataLoader(ctx);
}
return mSingletonInstance;
}
public RequestQueue getRequestQueue() {
if(mRequestQueue == null) {
mRequestQueue = Volley.newRequestQueue(mCtx.getApplicationContext());
}
return mRequestQueue;
}
public <T> void addToRequestQueue(Request<T> req) {
getRequestQueue().add(req);
}
}
