How to catch a Firebase Auth specific exceptions

Question

Using Firebase, how do I catch a specific exception and tell the user gracefully about it? E.g :

FirebaseAuthInvalidCredentialsException: The email address is badly formatted.

I'm using the code below to signup the user using email and password, but I'm not that advanced in java.

mAuth.createUserWithEmailAndPassword(email, pwd)
    .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {

    @Override
    public void onComplete(@NonNull Task<AuthResult> task) {
        if (!task.isSuccessful()) {
            //H.toast(c, task.getException().getMessage());
            Log.e("Signup Error", "onCancelled", task.getException());
        } else {
            FirebaseUser user = mAuth.getCurrentUser();
            String uid = user.getUid();
        }
    }    
});

Answer 1

You can throw the Exception returned by task.getException inside a try block and catch each type of Exception that may be thrown by the method you are using.

Here is an example from the OnCompleteListener for the createUserWithEmailAndPassword method.

if(!task.isSuccessful()) {
    try {
        throw task.getException();
    } catch(FirebaseAuthWeakPasswordException e) {
        mTxtPassword.setError(getString(R.string.error_weak_password));
        mTxtPassword.requestFocus();
    } catch(FirebaseAuthInvalidCredentialsException e) {
        mTxtEmail.setError(getString(R.string.error_invalid_email));
        mTxtEmail.requestFocus();
    } catch(FirebaseAuthUserCollisionException e) {
        mTxtEmail.setError(getString(R.string.error_user_exists));
        mTxtEmail.requestFocus();
    } catch(Exception e) {
        Log.e(TAG, e.getMessage());
    }
}

Answer 2

In addition to @pdegand59 answer, I found some error code in Firebase library and test on Android (the returned error code). Hope this helps, Regards.

 ("ERROR_INVALID_CUSTOM_TOKEN", "The custom token format is incorrect. Please check the documentation."));
 ("ERROR_CUSTOM_TOKEN_MISMATCH", "The custom token corresponds to a different audience."));
 ("ERROR_INVALID_CREDENTIAL", "The supplied auth credential is malformed or has expired."));
 ("ERROR_INVALID_EMAIL", "The email address is badly formatted."));
 ("ERROR_WRONG_PASSWORD", "The password is invalid or the user does not have a password."));
 ("ERROR_USER_MISMATCH", "The supplied credentials do not correspond to the previously signed in user."));
 ("ERROR_REQUIRES_RECENT_LOGIN", "This operation is sensitive and requires recent authentication. Log in again before retrying this request."));
 ("ERROR_ACCOUNT_EXISTS_WITH_DIFFERENT_CREDENTIAL", "An account already exists with the same email address but different sign-in credentials. Sign in using a provider associated with this email address."));
 ("ERROR_EMAIL_ALREADY_IN_USE", "The email address is already in use by another account."));
 ("ERROR_CREDENTIAL_ALREADY_IN_USE", "This credential is already associated with a different user account."));
 ("ERROR_USER_DISABLED", "The user account has been disabled by an administrator."));
 ("ERROR_USER_TOKEN_EXPIRED", "The user\'s credential is no longer valid. The user must sign in again."));
 ("ERROR_USER_NOT_FOUND", "There is no user record corresponding to this identifier. The user may have been deleted."));
 ("ERROR_INVALID_USER_TOKEN", "The user\'s credential is no longer valid. The user must sign in again."));
 ("ERROR_OPERATION_NOT_ALLOWED", "This operation is not allowed. You must enable this service in the console."));
 ("ERROR_WEAK_PASSWORD", "The given password is invalid."));
 ("ERROR_MISSING_EMAIL", "An email address must be provided.";

Answer 3

There are a number of exceptions associated with firebase auth. In addition to @kingspeech

You should use ((FirebaseAuthException)task.getException()).getErrorCode() to get the type of error and then handle it in switch like this :

private void loginUser(String email, String password) {

        mAuth.signInWithEmailAndPassword(email, password).addOnCompleteListener(new OnCompleteListener<AuthResult>() {

            @Override
            public void onComplete(@NonNull Task<AuthResult> task) {

                if (task.isSuccessful()) {

                    startActivity(new Intent(MainActivity.this, Main2Activity.class));

                } else {

                    String errorCode = ((FirebaseAuthException) task.getException()).getErrorCode();

                    switch (errorCode) {

                        case "ERROR_INVALID_CUSTOM_TOKEN":
                            Toast.makeText(MainActivity.this, "The custom token format is incorrect. Please check the documentation.", Toast.LENGTH_LONG).show();
                            break;

                        case "ERROR_CUSTOM_TOKEN_MISMATCH":
                            Toast.makeText(MainActivity.this, "The custom token corresponds to a different audience.", Toast.LENGTH_LONG).show();
                            break;

                        case "ERROR_INVALID_CREDENTIAL":
                            Toast.makeText(MainActivity.this, "The supplied auth credential is malformed or has expired.", Toast.LENGTH_LONG).show();
                            break;

                        case "ERROR_INVALID_EMAIL":
                            Toast.makeText(MainActivity.this, "The email address is badly formatted.", Toast.LENGTH_LONG).show();
                            etEmail.setError("The email address is badly formatted.");
                            etEmail.requestFocus();
                            break;

                        case "ERROR_WRONG_PASSWORD":
                            Toast.makeText(MainActivity.this, "The password is invalid or the user does not have a password.", Toast.LENGTH_LONG).show();
                            etPassword.setError("password is incorrect ");
                            etPassword.requestFocus();
                            etPassword.setText("");
                            break;

                        case "ERROR_USER_MISMATCH":
                            Toast.makeText(MainActivity.this, "The supplied credentials do not correspond to the previously signed in user.", Toast.LENGTH_LONG).show();
                            break;

                        case "ERROR_REQUIRES_RECENT_LOGIN":
                            Toast.makeText(MainActivity.this, "This operation is sensitive and requires recent authentication. Log in again before retrying this request.", Toast.LENGTH_LONG).show();
                            break;

                        case "ERROR_ACCOUNT_EXISTS_WITH_DIFFERENT_CREDENTIAL":
                            Toast.makeText(MainActivity.this, "An account already exists with the same email address but different sign-in credentials. Sign in using a provider associated with this email address.", Toast.LENGTH_LONG).show();
                            break;

                        case "ERROR_EMAIL_ALREADY_IN_USE":
                            Toast.makeText(MainActivity.this, "The email address is already in use by another account.   ", Toast.LENGTH_LONG).show();
                            etEmail.setError("The email address is already in use by another account.");
                            etEmail.requestFocus();
                            break;

                        case "ERROR_CREDENTIAL_ALREADY_IN_USE":
                            Toast.makeText(MainActivity.this, "This credential is already associated with a different user account.", Toast.LENGTH_LONG).show();
                            break;

                        case "ERROR_USER_DISABLED":
                            Toast.makeText(MainActivity.this, "The user account has been disabled by an administrator.", Toast.LENGTH_LONG).show();
                            break;

                        case "ERROR_USER_TOKEN_EXPIRED":
                            Toast.makeText(MainActivity.this, "The user\\'s credential is no longer valid. The user must sign in again.", Toast.LENGTH_LONG).show();
                            break;

                        case "ERROR_USER_NOT_FOUND":
                            Toast.makeText(MainActivity.this, "There is no user record corresponding to this identifier. The user may have been deleted.", Toast.LENGTH_LONG).show();
                            break;

                        case "ERROR_INVALID_USER_TOKEN":
                            Toast.makeText(MainActivity.this, "The user\\'s credential is no longer valid. The user must sign in again.", Toast.LENGTH_LONG).show();
                            break;

                        case "ERROR_OPERATION_NOT_ALLOWED":
                            Toast.makeText(MainActivity.this, "This operation is not allowed. You must enable this service in the console.", Toast.LENGTH_LONG).show();
                            break;

                        case "ERROR_WEAK_PASSWORD":
                            Toast.makeText(MainActivity.this, "The given password is invalid.", Toast.LENGTH_LONG).show();
                            etPassword.setError("The password is invalid it must 6 characters at least");
                            etPassword.requestFocus();
                            break;

                    }
                }
            }
        });
    }