Delegation Pattern for Sling Models returns null object

Hi @mohitkumark 

Please find the model class code snippet that I am using:

@Model(adaptables = { SlingHttpServletRequest.class}, adapters = {ComponentExporter.class,Navigation.class,NavigationCustomModel.class },
resourceType = "myproject/components/content/navigation", defaultInjectionStrategy = DefaultInjectionStrategy.OPTIONAL)
@Exporter(name = "gson", extensions = ExporterConstants.SLING_MODEL_EXTENSION)
public class NavigationCustomModel implements Navigation {

private static final Logger LOGGER = LoggerFactory.getLogger(NavigationCustomModel.class);
private static final String PN_ACCESSIBILITY_LABEL = "accessibilityLabel";

@Self
private SlingHttpServletRequest request;


@Self
@Via(type = ResourceSuperType.class)
@Delegate(excludes = DelegationExclusion.class)
private Navigation navigation;

/**
* The current page.
*/
@ScriptVariable
private Page currentPage;

/**
* The current style.
*/
@ScriptVariable
private Style currentStyle;

/**
* The language manager service.
*/
@OSGiService
private LanguageManager languageManager;

/**
* The relationship manager service.
*/
@OSGiService
private LiveRelationshipManager relationshipManager;

/**
* The accessibility label.
*/

private String accessibilityLabel;

@Inject
private Resource resource;


@JsonIgnore
private List<NavigationItem> items;

static final String PN_DISABLE_SHADOWING = "disableShadowing";

/**
* Initialize the model.
*/
@PostConstruct
private void initModel() {
ValueMap properties = this.resource.getValueMap();
items = getItems();
}

@Override
public List<NavigationItem> getItems() {
return nav.getItems();
}

@Override
public String getAccessibilityLabel() {
if (this.accessibilityLabel == null) {
this.accessibilityLabel = this.resource.getValueMap().get(PN_ACCESSIBILITY_LABEL, String.class);
}
return this.accessibilityLabel;
}

And in servlet I am trying to initiate the object of this model class using adapt to but I am getting null value.:-

Resource resource = req.getResourceResolver().getResource("/content/hq/en/testpage");
NavigationCustomModel navigation = resource.adaptTo(NavigationCustomModel.class);