Optionals

Many of the component and page decorator methods return an Optional wrapper for nullable values. See the Google Guava user guide for a more thorough explanation, but here are a few examples of Optional usage in the AEM context:

String href = getAsHref("path").or("#");
String redirectHref = getAsHref("redirectPath").or(currentPage.getHref());

Optional<PageDecorator> pageOptional = getAsPage("pagePath");

if (pageOptional.isPresent()) {
    PageDecorator page = pageOptional.get();
    String title = page.getNavigationTitleOptional().or(page.getTitle());

    ...
}

The Javadoc has the complete list of available methods.