Question

I wanted to fetch the user details like name, email id and image when a user logs in with google on the navigation drawer header. I successfully authenticated the user via Google sign in but the app crashes while setting name email and picture on the drawer.

The error shows:

java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.String.replace(java.lang.CharSequence, java.lang.CharSequence)' on a null object reference

And the code related to it is

        FirebaseDatabase.getInstance().getReference(Constants.USER_KEY).child(mFirebaseUser.getEmail().replace(".", ","))
            .addListenerForSingleValueEvent(new ValueEventListener() {
                @Override
                public void onDataChange(DataSnapshot dataSnapshot) {
                    if (dataSnapshot.getValue() != null){
                        Users users = dataSnapshot.getValue(Users.class);
                        Glide.with(MainActivity.this)
                                .load(users.getPhotoUrl())
                                .into(mDisplayImageView);
                        mNameTextView.setText(users.getUser());
                        mEmailTextView.setText(users.getEmail());
                    }
                }

                @Override
                public void onCancelled(DatabaseError databaseError) {

                }
            });

Is there any way to fix this issue? Or an alternative way?

Answer 1

您的错误消息会告诉您代码中的确切问题。因此，您要调用replace()方法on a null object reference。这意味着mFirebaseUser.getEmail()返回null。要解决此问题，您需要在实际使用它之前实例化mFirebaseUser对象，如下所示：

FirebaseUser mFirebaseUser = FirebaseAuth.getInstance().getCurrentUser();

要获取用户电子邮件，只需使用以下代码行：

if (mFirebaseUser == null) {
    String userEmail = mFirebaseUser.getEmail();
}

How to display user details like name, email and image on navigation drawer on Google Sign In?

1 个答案: