I am trying to run my app using Adapters and I am getting this error while doing that:
Mentioning that there are 3 adapters: ReviewsAdapter, StandupWithKey and VideoAdapter.
05-07 20:16:57.707 5326-5326/com.example.sefi.authenticationproject E/ReviewsAdapter: onBindViewHolder() >> 0 05-07 20:16:57.708 5326-5326/com.example.sefi.authenticationproject E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.sefi.authenticationproject, PID: 5326 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference at com.example.sefi.authenticationproject.adapter.ReviewsAdapter.onBindViewHolder(ReviewsAdapter.java:48) at com.example.sefi.authenticationproject.adapter.ReviewsAdapter.onBindViewHolder(ReviewsAdapter.java:18) at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6482) at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6515) at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5458) at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5724) at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5563) at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5559) at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2229) at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1556) at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1516) at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:608) at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3693) at android.support.v7.widget.RecyclerView.onMeasure(RecyclerView.java:3109) at android.view.View.measure(View.java:19734) at android.support.constraint.ConstraintLayout.internalMeasureChildren(ConstraintLayout.java:1210) at android.support.constraint.ConstraintLayout.onMeasure(ConstraintLayout.java:1550) at android.view.View.measure(View.java:19734) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6120) at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) at android.view.View.measure(View.java:19734) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6120) at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1464) at android.widget.LinearLayout.measureVertical(LinearLayout.java:758) at android.widget.LinearLayout.onMeasure(LinearLayout.java:640) at android.view.View.measure(View.java:19734) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6120) at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) at com.android.internal.policy.DecorView.onMeasure(DecorView.java:687) at android.view.View.measure(View.java:19734) at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2271) at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1358) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1607) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1246) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6301) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:871) at android.view.Choreographer.doCallbacks(Choreographer.java:683) at android.view.Choreographer.doFrame(Choreographer.java:619) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:857) at android.os.Handler.handleCallback(Handler.java:751) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:154) at android.app.ActivityThread.main(ActivityThread.java:6077) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
And this are my files:
ReviewsAdapter.java
public class ReviewsAdapter extends RecyclerView.Adapter<ReviewsAdapter.ReviewViewHolder> { private final String TAG = "ReviewsAdapter"; private List<Review> reviewsList; public ReviewsAdapter(List<Review> reviewsList) { this.reviewsList = reviewsList; } @Override public ReviewViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { Log.e(TAG,"onCreateViewHolder() >>"); View itemView = LayoutInflater.from(parent.getContext()) .inflate(R.layout.activity_standup_details, parent, false); Log.e(TAG,"onCreateViewHolder() <<"); return new ReviewViewHolder(parent.getContext(),itemView); } @Override public void onBindViewHolder(ReviewViewHolder holder, int position) { Log.e(TAG,"onBindViewHolder() >> " + position); Review review = reviewsList.get(position); holder.getUserMail().setText(review.getUserEmail()); holder.getUserReview().setText(review.getUserReview()); holder.getUserRating().setRating(review.getUserRating()); Log.e(TAG,"onBindViewHolder() << "+ position); } @Override public int getItemCount() { return reviewsList.size(); } public class ReviewViewHolder extends RecyclerView.ViewHolder { private TextView userReview; private TextView userMail; private RatingBar userRating; public ReviewViewHolder(Context context, View view) { super(view); userReview = (TextView) view.findViewById(R.id.user_review); userMail = (TextView) view.findViewById(R.id.user_mail); userRating = (RatingBar) view.findViewById(R.id.user_rating); } public TextView getUserReview() { return userReview; } public void setUserReview(TextView userReview) { this.userReview = userReview; } public TextView getUserMail() { return userMail; } public void setUserMail(TextView userMail) { this.userMail = userMail; } public RatingBar getUserRating() { return userRating; } public void setUserRating(RatingBar userRating) { this.userRating = userRating; } } } StandupDetails.java
public class StandupDetails extends Activity { public final String TAG = "StandupDetails"; private Standup standup; private String key; private User user; private FloatingActionButton writeReview; private Button buyPlay; private MediaPlayer mediaPlayer; private RecyclerView recyclerViewStandupReviews; private DatabaseReference standupReviewsRef; private List<Review> reviewsList = new ArrayList<>(); private boolean standupWasPurchased; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_standup_details); key = getIntent().getStringExtra("key"); standup = getIntent().getParcelableExtra("standup"); user = getIntent().getParcelableExtra("user"); mediaPlayer = new MediaPlayer(); mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); StorageReference thumbRef = FirebaseStorage .getInstance() .getReference() .child("thumbs/" + standup.getThumbImage()); // Load the image using Glide thumbRef.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() { @Override public void onSuccess(Uri uri) { Glide.with(StandupDetails.this).load(uri) .into((ImageView)findViewById(R.id.imageViewSong)); } }); ((TextView) findViewById(R.id.textViewName)).setText(standup.getName()); buyPlay = ((Button) findViewById(R.id.buttonBuyPlay)); buyPlay.setText("BUY $" + standup.getPrice()); Iterator i = user.getMyStandups().iterator(); while (i.hasNext()) { if (i.next().equals(key)) { standupWasPurchased = true; buyPlay.setText("PLAY"); break; } } buyPlay.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Log.e(TAG, "buyPlay.onClick() >> file=" + standup.getName()); FirebaseUser fbUser = FirebaseAuth.getInstance().getCurrentUser(); String info = fbUser.getProviderId(); if (standupWasPurchased) { Log.e(TAG, "buyPlay.onClick() >> Playing purchased standup"); //User purchased the standup so he can play it playCurrentStandup(standup.getFile()); } else{ Log.e(TAG, "buyPlay.onClick() >> Purchase the standup"); user.getMyStandups().add(key); user.upgdateTotalPurchase(standup.getPrice()); DatabaseReference userRef = FirebaseDatabase.getInstance().getReference("Users"); userRef.child(FirebaseAuth.getInstance().getCurrentUser().getUid()).setValue(user); standupWasPurchased = true; buyPlay.setText("PLAY"); } Log.e(TAG, "playStandup.onClick() <<"); } }); writeReview = (FloatingActionButton) findViewById(R.id.buttonNewReview); writeReview.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Log.e(TAG, "writeReview.onClick() >>"); Intent intent = new Intent(getApplicationContext(),ReviewActivity.class); intent.putExtra("standup", standup); intent.putExtra("key", key); intent.putExtra("user",user); startActivity(intent); finish(); Log.e(TAG, "writeReview.onClick() <<"); } }); recyclerViewStandupReviews = findViewById(R.id.standup_reviews); recyclerViewStandupReviews.setHasFixedSize(true); recyclerViewStandupReviews.setLayoutManager(new LinearLayoutManager(getApplicationContext())); recyclerViewStandupReviews.setItemAnimator(new DefaultItemAnimator()); ReviewsAdapter reviewsAdapter = new ReviewsAdapter(reviewsList); recyclerViewStandupReviews.setAdapter(reviewsAdapter); standupReviewsRef = FirebaseDatabase.getInstance().getReference("Standup/" + key +"/reviews"); standupReviewsRef.addListenerForSingleValueEvent(new ValueEventListener() { @Override public void onDataChange(DataSnapshot snapshot) { Log.e(TAG, "onDataChange() >> Standup/" + key); for (DataSnapshot dataSnapshot : snapshot.getChildren()) { Review review = dataSnapshot.getValue(Review.class); reviewsList.add(review); } recyclerViewStandupReviews.getAdapter().notifyDataSetChanged(); Log.e(TAG, "onDataChange(Review) <<"); } @Override public void onCancelled(DatabaseError databaseError) { Log.e(TAG, "onCancelled(Review) >>" + databaseError.getMessage()); } }); Log.e(TAG, "onCreate() <<"); } @Override protected void onPause() { super.onPause(); stopPlayingCurrentStandup(); } private void playCurrentStandup(String standupFile) { Log.e(TAG, "playCurrentStandup() >> standupFile=" + standupFile); if (stopPlayingCurrentStandup()) { Log.e(TAG, "playCurrentStandup() << Stop playing current Standup"); return; } FirebaseStorage.getInstance() .getReference("StandupsFile/" + standupFile) .getDownloadUrl() .addOnSuccessListener(new OnSuccessListener<Uri>() { @Override public void onSuccess(Uri downloadUrl) { Log.e(TAG, "onSuccess() >> " + downloadUrl.toString()); try { Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(downloadUrl.toString())); intent.setDataAndType(Uri.parse(downloadUrl.toString()), "video/mp4"); startActivity(intent); //mediaPlayer.setDataSource(downloadUrl.toString()); //mediaPlayer.prepare(); // might take long! (for buffering, etc) //mediaPlayer.start(); } catch (Exception e) { Log.w(TAG, "playStandup() error:" + e.getMessage()); } Log.e(TAG, "onSuccess() <<"); } }); Log.e(TAG, "playCurrentStandup() << "); } private boolean stopPlayingCurrentStandup() { if (mediaPlayer.isPlaying()) { Log.e(TAG, "onSuccess() >> Stop the media player"); //Stop the media player mediaPlayer.stop(); mediaPlayer.reset(); buyPlay.setText("PLAY"); return true; } return false; } } ReviewActivity
public class ReviewActivity extends AppCompatActivity { private final String TAG = "ReviewActivity"; private Standup standup; private String key; private User user; private int prevRating = -1; private TextView userReview; private RatingBar userRating; private DatabaseReference standupRef; @Override protected void onCreate(Bundle savedInstanceState) { Log.e(TAG, "onCreate() >>"); super.onCreate(savedInstanceState); setContentView(R.layout.activity_review); key = getIntent().getStringExtra("key"); standup = getIntent().getParcelableExtra("standup"); user = getIntent().getParcelableExtra("user"); userReview = findViewById(R.id.new_user_review); userRating = findViewById(R.id.new_user_rating); standupRef = FirebaseDatabase.getInstance().getReference("Standup/" + key); standupRef.child("/reviews/" + FirebaseAuth.getInstance().getCurrentUser().getUid()). addListenerForSingleValueEvent(new ValueEventListener() { @Override public void onDataChange(DataSnapshot snapshot) { Log.e(TAG, "onDataChange(Review) >> " + snapshot.getKey()); Review review = snapshot.getValue(Review.class); if (review != null) { userReview.setText(review.getUserReview()); userRating.setRating(review.getUserRating()); prevRating = review.getUserRating(); } Log.e(TAG, "onDataChange(Review) <<"); } @Override public void onCancelled(DatabaseError databaseError) { Log.e(TAG, "onCancelled(Review) >>" + databaseError.getMessage()); } }); Log.e(TAG, "onCreate() <<"); } public void onSubmitClick(View v) { Log.e(TAG, "onSubmitClick() >>"); standupRef.runTransaction(new Transaction.Handler() { @Override public Transaction.Result doTransaction(MutableData mutableData) { Log.e(TAG, "doTransaction() >>" ); Standup standup = mutableData.getValue(Standup.class); if (standup == null ) { Log.e(TAG, "doTransaction() << standup is null" ); return Transaction.success(mutableData); } if (prevRating == -1) { // Increment the review count and rating only in case the user enters a new review standup.incrementReviewCount(); standup.incrementRating((int)userRating.getRating()); } else{ standup.incrementRating((int)userRating.getRating() - prevRating); } mutableData.setValue(standup); Log.e(TAG, "doTransaction() << standup was set"); return Transaction.success(mutableData); } @Override public void onComplete(DatabaseError databaseError, boolean committed, DataSnapshot dataSnapshot) { Log.e(TAG, "onComplete() >>" ); if (databaseError != null) { Log.e(TAG, "onComplete() << Error:" + databaseError.getMessage()); return; } if (committed) { Review review = new Review( userReview.getText().toString(), (int)userRating.getRating(), user.getEmail()); standupRef.child("/reviews/" + FirebaseAuth.getInstance().getCurrentUser().getUid()).setValue(review); } Intent intent = new Intent(getApplicationContext(),StandupDetails.class); intent.putExtra("standup", standup); intent.putExtra("key", key); intent.putExtra("user",user); startActivity(intent); finish(); Log.e(TAG, "onComplete() <<" ); } }); Log.e(TAG, "onSubmitClick() <<"); } } StandupPlayerMain.java
public class StandupPlayerMain extends Activity { private final String TAG = "StandUp Player Tag"; private DatabaseReference allStandupRef; private DatabaseReference myUserRef; private List<StandupWithKey> standupList = new ArrayList<>(); private GoogleSignInClient mGoogleSignInClient; private RecyclerView recyclerView; private VideoAdapter standupAdapter; private User myUser; private FirebaseAuth mAuth; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_standup_player_main); Log.e(TAG, "onCreate() >>"); mAuth= FirebaseAuth.getInstance(); recyclerView = (RecyclerView) findViewById(R.id.standups_list); recyclerView.setHasFixedSize(true); recyclerView.setLayoutManager(new LinearLayoutManager(getApplicationContext())); recyclerView.setItemAnimator(new DefaultItemAnimator()); FirebaseUser fbUser = FirebaseAuth.getInstance().getCurrentUser(); if (fbUser != null) { myUserRef = FirebaseDatabase.getInstance().getReference("Users/" + fbUser.getUid()); myUserRef.addValueEventListener(new ValueEventListener() { @Override public void onDataChange(DataSnapshot snapshot) { Log.e(TAG, "onDataChange(User) >> " + snapshot.getKey()); myUser = snapshot.getValue(User.class); getAllStandups(); Log.e(TAG, "onDataChange(User) <<"); } @Override public void onCancelled(DatabaseError databaseError) { Log.e(TAG, "onCancelled(Users) >>" + databaseError.getMessage()); } }); Log.e(TAG, "onCreate() <<"); } else { getAllStandups(); } } private void getAllStandups() { Log.e(TAG,"GET ALL STANDUPS >>"); standupList.clear(); standupAdapter = new VideoAdapter(standupList,myUser); recyclerView.setAdapter(standupAdapter); //getAllSongsUsingValueListenrs(); getAllVideoUsingChildListenrs(); Log.e(TAG,"GET ALL STANDUPS <<"); } private void getAllVideoUsingChildListenrs() { allStandupRef = FirebaseDatabase.getInstance().getReference("Standup"); allStandupRef.addValueEventListener(new ValueEventListener() { @Override public void onDataChange(DataSnapshot snapshot) { Log.e(TAG, "onDataChange(Standup) >> " + snapshot.getKey()); updateStandupList(snapshot); Log.e(TAG, "onDataChange(Standup) <<"); } @Override public void onCancelled(DatabaseError databaseError) { Log.e(TAG, "onCancelled(Songs) >>" + databaseError.getMessage()); } }); } private void getAllSongsUsingChildListenrs() { allStandupRef = FirebaseDatabase.getInstance().getReference("Standup"); allStandupRef.addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot snapshot, String previousChildName){ Log.e(TAG, "onChildAdded(Standup) >> " + snapshot.getKey()); StandupWithKey standupwithKey = new StandupWithKey(snapshot.getKey(),snapshot.getValue(Standup.class)); standupList.add(standupwithKey); recyclerView.getAdapter().notifyDataSetChanged(); Log.e(TAG, "onChildAdded(Standup) <<"); } @Override public void onChildChanged(DataSnapshot snapshot, String previousChildName){ Log.e(TAG, "onChildChanged(Standup) >> " + snapshot.getKey()); Standup standup = snapshot.getValue(Standup.class); String key = snapshot.getKey(); for (int i = 0 ; i < standupList.size() ; i++) { StandupWithKey standupWithKey = (StandupWithKey) standupList.get(i); if (standupWithKey.getKey().equals(snapshot.getKey())) { standupWithKey.setStandup(standup); recyclerView.getAdapter().notifyDataSetChanged(); break; } } Log.e(TAG, "onChildChanged(Standup) <<"); } @Override public void onChildMoved(DataSnapshot snapshot, String previousChildName){ Log.e(TAG, "onChildMoved(Standup) >> " + snapshot.getKey()); Log.e(TAG, "onChildMoved(Standup) << Doing nothing"); } @Override public void onChildRemoved(DataSnapshot snapshot){ Log.e(TAG, "onChildRemoved(Standup) >> " + snapshot.getKey()); Standup standup =snapshot.getValue(Standup.class); String key = snapshot.getKey(); for (int i = 0 ; i < standupList.size() ; i++) { StandupWithKey standupwithKey = (StandupWithKey) standupList.get(i); if (standupwithKey.getKey().equals(snapshot.getKey())) { standupList.remove(i); recyclerView.getAdapter().notifyDataSetChanged(); Log.e(TAG, "onChildRemoved(Standup) >> i="+i); break; } } Log.e(TAG, "onChildRemoved(Standup) <<"); } @Override public void onCancelled(DatabaseError databaseError) { Log.e(TAG, "onCancelled(Standup) >>" + databaseError.getMessage()); } }); } private void updateStandupList(DataSnapshot snapshot) { for (DataSnapshot dataSnapshot : snapshot.getChildren()) { Standup standup = dataSnapshot.getValue(Standup.class); Log.e(TAG, "updateStandupList() >> adding standup: " + standup.getName()); String key = dataSnapshot.getKey(); standupList.add(new StandupWithKey(key,standup)); } recyclerView.getAdapter().notifyDataSetChanged(); } public void onSignOutClick(View V) { Log.e(TAG, "onSignOutClick() >>"); logOutFromGoogleAccount(); LoginManager.getInstance().logOut(); mAuth.signOut(); Intent intent = new Intent(StandupPlayerMain.this,LogInActivity.class); startActivity(intent); Log.e(TAG, "onSignOutClick() <<"); } private void logOutFromGoogleAccount() { Log.e(TAG, "logOutFromGoogleAccount() >>"); GoogleSignInOptions gso = new GoogleSignInOptions .Builder(GoogleSignInOptions.DEFAULT_SIGN_IN) .requestIdToken(getString(R.string.default_web_client_id)) .requestProfile() .requestEmail() .build(); // Build a GoogleSignInClient with the options specified by gso. mGoogleSignInClient = GoogleSignIn.getClient(this, gso); mGoogleSignInClient.signOut(); Log.e(TAG, "logOutFromGoogleAccount() <<"); } public void onSearchButtonClick(View v) { String searchString = ((EditText)findViewById(R.id.edit_text_search_standup)).getText().toString(); String orderBy = ((RadioButton)findViewById(R.id.radioButtonByReviews)).isChecked() ? "reviewsCount" : "price"; Query searchStandup; Log.e(TAG, "onSearchButtonClick() >> searchString="+searchString+ ",orderBy="+orderBy); standupList.clear(); if (searchString != null && !searchString.isEmpty()) { searchStandup = allStandupRef.orderByChild("name").startAt(searchString).endAt(searchString + "\uf8ff"); } else { searchStandup = allStandupRef.orderByChild(orderBy); } searchStandup.addValueEventListener(new ValueEventListener() { @Override public void onDataChange(DataSnapshot snapshot) { Log.e(TAG, "onDataChange(Query) >> " + snapshot.getKey()); updateStandupList(snapshot); Log.e(TAG, "onDataChange(Query) <<"); } @Override public void onCancelled(DatabaseError databaseError) { Log.e(TAG, "onCancelled() >>" + databaseError.getMessage()); } }); Log.e(TAG, "onSearchButtonClick() <<"); } public void onRadioButtonCLick(View v) { switch (v.getId()) { case R.id.radioButtonByPrice: ((RadioButton)findViewById(R.id.radioButtonByReviews)).setChecked(false); break; case R.id.radioButtonByReviews: ((RadioButton)findViewById(R.id.radioButtonByPrice)).setChecked(false); break; } } } 
