Is there similar way to pagefactory (iOSXcuitFindBy/AndroidFindby) to handle dynamic element identifiers?

Question

I have a hybrid app, which have the same features on iOS and Android. I want to use one repository to automate both platform. How can I identify the element for both platform without a if-else statement?

   public class LoginPage extends BasePage {

    String alertmsg;

    @AndroidFindBy(xpath = "dynamic identifier....")
    @iOSXCUITFindBy**(xpath= "//XCUIElementTypeStaticText[`name == \""+alertmsg+"\"`]")**
    public WebElement alertBanner;

    @AndroidFindBy(xpath = "//android.widget.EditText[@resource-id=\"username\"]")
    @iOSXCUITFindBy(xpath = "//XCUIElementTypeTextField")
    public WebElement usernameInputField;

    @AndroidFindBy(xpath = "//android.widget.EditText[@resource-id=\"password\"]")
    @iOSXCUITFindBy(xpath = "//XCUIElementTypeSecureTextField")
    public WebElement passwordInputField;

    @AndroidFindBy(xpath = "//android.widget.Button[@text=\"Log in\"]")
    @iOSXCUITFindBy(xpath = "//XCUIElementTypeButton[@name='Log in' or @name='Anmelden']")
    public WebElement loginBtn;

    public void peformLogin(String username, String password){
        usernameInputField.click();
        usernameInputField.sendKeys(username);
        passwordInputField.click();
        passwordInputField.sendKeys(password);
        loginBtn.click();
    }

    public void setAlertBannerTxt(String  bannerTxt){
        alertmsg = bannerTxt;
    }


}

I tried to pass the concatenated xpath to the @iOSXCUITFindBy annotation, but it won't work, since the value is not present at the instantiation.