Sample Code ( Firebase Authentication)

Firebase (Authentication)

1. Sign up

firebaseAuth.createUserWithEmailAndPassword(email, pwd).addOnCompleteListener(SignUpActivity.this, new OnCompleteListener() {
                        @Override
                        public void onComplete(@NonNull Task task) {

                            if (task.isSuccessful()) {
                                mDialog.dismiss();


                                FirebaseUser user = firebaseAuth.getCurrentUser();
                                String uid = user.getUid();
                                String name = mName.getText().toString().trim();


                                HashMap hashMap = new HashMap<>();
                                hashMap.put("uid", uid);
                                hashMap.put("email", email);
                                hashMap.put("name",name);

                                FirebaseDatabase database = FirebaseDatabase.getInstance();
                                DatabaseReference reference = database.getReference("Users");
                                reference.child(uid).setValue(hashMap);


                                Intent intent = new Intent(SignUpActivity.this, LoginActivity.class);
                                startActivity(intent);
                                finish();
                                Toast.makeText(SignUpActivity.this, "회원가입에 성공하셨습니다.", Toast.LENGTH_SHORT).show();

                  }

2. Login

 firebaseAuth.signInWithEmailAndPassword(email, pwd).addOnCompleteListener(LoginActivity.this, new OnCompleteListener() {
                                @Override
                                public void onComplete(@NonNull Task task) {
                                    if (task.isSuccessful()) {
                                        Intent intent = new Intent(LoginActivity.this, MainActivity.class);
                                        startActivity(intent);
                                        Toast.makeText(LoginActivity.this, "Login Successful", Toast.LENGTH_SHORT).show();
                                    }

3. My Profile

final FirebaseAuth firebaseAuth = FirebaseAuth.getInstance();

        if (firebaseAuth.getCurrentUser() != null) {
            firebaseUser = firebaseAuth.getCurrentUser();
        }
        if (firebaseUser != null) {
            // Name, email address, and profile photo Url
            // Get a reference to your user
            final FirebaseDatabase database = FirebaseDatabase.getInstance();
            DatabaseReference ref = database.getReference("server/path/to/profile");
            String name = firebaseUser.getDisplayName();
            String email = firebaseUser.getEmail();
            user_name.setText(name);
            user_email.setText(email);
            user_name.setText(firebaseUser.getDisplayName());

            imageView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    openGallery();
                }
            });
            pictureListener = new PictuteListener() {
                @Override
                public void onProfilePictureUpdated() {
                    Uri uri = firebaseUser.getPhotoUrl();
                    Glide.with(getActivity()).load(uri).into(imageView);
                }
            };
            Uri profilePicture = firebaseUser.getPhotoUrl();
            Glide.with(this).load(profilePicture).placeholder(R.drawable.profile_image).into(imageView);
        }