无法使用 firebase 创建帐户？

Question

i tried to do everything correctly and can't seem to find what's wrong here, i even created the project again from scratch but still it doesn't work, but i get the "failed" toast when trying to create an account, i added the internet permission too. i also don't get any error in logcat to show it here, how can this be solved ?

public class CreateAccountActivity extends AppCompatActivity {

private Button btnCreateAcc;

private FirebaseAuth firebaseAuth;
private FirebaseAuth.AuthStateListener authStateListener;
private FirebaseUser currentUser;

// firestore
private FirebaseFirestore database = FirebaseFirestore.getInstance();

private CollectionReference collectionReference = database.collection("Users");

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_create_account);

    firebaseAuth = FirebaseAuth.getInstance();
    authStateListener = new FirebaseAuth.AuthStateListener() {
        @Override
        public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
            currentUser = firebaseAuth.getCurrentUser();

            if (currentUser != null) {

            } else {

            }
        }
    };

    btnCreateAcc = findViewById(R.id.create_acct_button);

    btnCreateAcc.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (!TextUtils.isEmpty(etEmail.getText().toString()) &&
                    !TextUtils.isEmpty(etPassword.getText().toString()) &&
                    !TextUtils.isEmpty(etUserName.getText().toString())) {

                String email = etEmail.getText().toString();
                String password = etPassword.getText().toString();
                String username = etUserName.getText().toString();

                createUserEmailAccount(email, password, username);
            } else {
                Toast.makeText(CreateAccountActivity.this, "Please fill in all fields"
                        , Toast.LENGTH_SHORT).show();
            }

        }
    });
}

private void createUserEmailAccount(String email, String password, final String username) {
    if (!TextUtils.isEmpty(email) && !TextUtils.isEmpty(password) &&
            !TextUtils.isEmpty(username)) {

        progressBar.setVisibility(View.VISIBLE);

        firebaseAuth.createUserWithEmailAndPassword(email, password)
                .addOnCompleteListener(new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        if (task.isSuccessful()) {
                            currentUser = firebaseAuth.getCurrentUser();

                            assert currentUser != null;
                            final String currentUserId = currentUser.getUid();

                            Map<String, String> userObj = new HashMap<>();
                            userObj.put("userId", currentUserId);
                            userObj.put("username", username);

                            collectionReference.add(userObj)
                                    .addOnSuccessListener(new OnSuccessListener<DocumentReference>() {
                                        @Override
                                        public void onSuccess(DocumentReference documentReference) {
                                            documentReference.get()
                                                    .addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
                                                        @Override
                                                        public void onComplete(@NonNull Task<DocumentSnapshot> task) {
                                                            if (Objects.requireNonNull(task.getResult()).exists()) {
                                                                progressBar.setVisibility(View.INVISIBLE);

                                                                String name = task.getResult()
                                                                        .getString("username");

                                                                Intent intent = new Intent(CreateAccountActivity.this,
                                                                        PostJournalActivity.class);
                                                                intent.putExtra("username", name);
                                                                intent.putExtra("userId", currentUserId);
                                                                startActivity(intent);
                                                            } else {
                                                                progressBar.setVisibility(View.INVISIBLE);
                                                            }
                                                        }
                                                    });
                                        }
                                    })
                                    .addOnFailureListener(new OnFailureListener() {
                                        @Override
                                        public void onFailure(@NonNull Exception e) {
                                            Toast.makeText(CreateAccountActivity.this, "failed"
                                                    , Toast.LENGTH_SHORT).show();
                                        }
                                    });
                        } else {
                            Toast.makeText(CreateAccountActivity.this, "failed task"
                                    , Toast.LENGTH_SHORT).show();
                        }
                    }
                })
                .addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception e) {
                        Toast.makeText(CreateAccountActivity.this, "failed on complete"
                                , Toast.LENGTH_SHORT).show();
                    }
                });

    } else {
        Toast.makeText(this, "failed else", Toast.LENGTH_SHORT).show();
    }
}

@Override
protected void onStart() {
    super.onStart();

    currentUser = firebaseAuth.getCurrentUser();
    firebaseAuth.addAuthStateListener(authStateListener);

}
}

Answer 1

i fixed, the problem was i had allow read, write: if false; in firestore and it needed to be allow read, write: if true;

Answer 2

This could be solved by following good debugging practices.

Meaningful error messages

When you encounter an error and wish to send a toast/alert to the user, send something meaningful to inform them what went wrong. As an example, instead of "failed" or "failed task", use "failed to upload user data" or "failed to create new user".

Each function will normally return a handful of exception classes that can be used to provide a better toast/alert message. Consulting the documentation for createUserWithEmailAndPassword(email, password) you can see what exceptions are thrown and use instanceof to determine the cause of the problem. For example, if e instanceof FirebaseAuthInvalidCredentialsException was true , you could toast "failed to create new user: invalid email".

While this seems tedious, it will save head-scratching later when a user encounters a problem and sends you a bug report/email about it. These steps will help you find any issues without needing access to logs for trivial problems such as incorrectly filled forms.

Log exceptions

The reason you have no information on what went wrong is because you haven't made use of the exception provided in each onFailure handler ( public void onFailure(@NonNull Exception e) { ... } ). These handlers provide you with the exception that caused the problem which you can save to the log using Log.e("yourActivityName:yourFunctionName", "short message", e) . You can also use e.getMessage() to get information about the thrown error.

In an onComplete(Task<?> task) handler, if task.isSuccessful() returns false , you can find out why it is false by calling Exception e = task.getException() and then log it.

Fail-fast programming

If you ever find that you have an if - else pair where the if section contains lots more code than the else section, it is likely to be a sign that you should flip the condition.

Whilst keeping your code cleaner by using less indentation, it also avoids having to scroll through a long if that probably contains more if and else statements.

For example,

if (!requiredVariable1.isEmpty() && !requiredVariable2.isEmpty()) {
    // ...
    // many (nested) lines of code
    // ...
} else {
    Log.e(TAG, "a required variable was empty");
}

if (requiredVariable1.isEmpty() || requiredVariable2.isEmpty()) {
    Log.e(TAG, "a required variable was empty");
    return;
}

// ...
// many lines of code
// ...

Example

As an example of applying these changes, I have made edits to the code you provided applying fail-fast techniques, simplifying error handling, logging exceptions, using OnSuccessListener and OnFailureListener instead of OnCompleteListener where appropriate,

private void createUserEmailAccount(String email, String password, final String username) {
    if (TextUtils.isEmpty(email) || TextUtils.isEmpty(password) || TextUtils.isEmpty(username)) {
        Toast.makeText(this, "Please fill in all fields", Toast.LENGTH_SHORT).show();
        return;
    }

    progressBar.setVisibility(View.VISIBLE);

    firebaseAuth.createUserWithEmailAndPassword(email, password)
        .addOnSuccessListener(new OnSuccessListener<AuthResult>() {
            @Override
            public void onSuccess(@NonNull Task<AuthResult> task) {
                currentUser = firebaseAuth.getCurrentUser();

                assert currentUser != null;
                final String currentUserId = currentUser.getUid();

                Map<String, String> userObj = new HashMap<>();
                userObj.put("userId", currentUserId);
                userObj.put("username", username); // unknown source for variable: username

                collectionReference.add(userObj)
                    .addOnSuccessListener(new OnSuccessListener<DocumentReference>() {
                        @Override
                        public void onSuccess(DocumentReference documentReference) {
                            documentReference.get() // why redownload from database? you could just use values of "userObj"
                                .addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
                                    @Override
                                    public void onComplete(@NonNull Task<DocumentSnapshot> task) {
                                        progressBar.setVisibility(View.INVISIBLE);

                                        if (!task.isSuccessful()
                                          || !Objects.requireNonNull(task.getResult()).exists()) {
                                            // show a error message?
                                            return;
                                        }

                                        String name = task.getResult()
                                                .getString("username");

                                        Intent intent = new Intent(CreateAccountActivity.this,
                                                PostJournalActivity.class);
                                        intent.putExtra("username", name);
                                        intent.putExtra("userId", currentUserId);
                                        startActivity(intent);
                                    }
                                });
                        }
                    })
                    .addOnFailureListener(new OnFailureListener() {
                        @Override
                        public void onFailure(@NonNull Exception e) {
                            Toast.makeText(CreateAccountActivity.this, "failed to add user data"
                                    , Toast.LENGTH_SHORT).show();
                            Log.e("CreateAccountActivity", "failed to add user data", e); // log error to logcat
                        }
                    });

            }
        })
        .addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                Toast.makeText(CreateAccountActivity.this, "failed to create user"
                        , Toast.LENGTH_SHORT).show();
                Log.e("CreateAccountActivity", "failed to create user", e); // log error to logcat
            }
        });
}