PasswordConfirmationStream.java

Observable<Boolean> passwordConfirmationStream = Observable.merge(
        RxTextView.textChanges(etPassword)
                .map(new Func1<CharSequence, Boolean>() {
                    @Override
                    public Boolean call(CharSequence charSequence) {
                        return !charSequence.toString().trim().equals(etPasswordConfirmation.getText().toString());
                    }
                }),
        RxTextView.textChanges(etPasswordConfirmation)
                .map(new Func1<CharSequence, Boolean>() {
                    @Override
                    public Boolean call(CharSequence charSequence) {
                        return !charSequence.toString().trim().equals(etPassword.getText().toString());
                    }
                })
);

Observer<Boolean> passwordConfirmationObserver = new Observer<Boolean>() {
    @Override
    public void onCompleted() {
        Log.d("rx","Password confirmation stream completed");
    }

    @Override
    public void onError(Throwable e) {
        Log.d("rx",e.getMessage());
    }

    @Override
    public void onNext(Boolean passwordConfirmationDontMatch) {
        Log.d("passwordConfirmation",String.valueOf(passwordConfirmationDontMatch.booleanValue()));
        showPasswordConfirmationAlert(passwordConfirmationDontMatch.booleanValue());
    }
};

public void showPasswordConfirmationAlert(boolean value){
        if(value){
            textPasswordConfirmationAlert.setText(R.string.password_confirmation_does_not_match_alert);
            textPasswordConfirmationAlert.setVisibility(View.VISIBLE);
        } else {
            textPasswordConfirmationAlert.setVisibility(View.GONE);
        }
}

passwordConfirmationStream.subscribe(passwordConfirmationObserver);