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aem - 无法将模型类适配到 SlingHttpServletRequest

问题描述

我正在尝试在我的模型类中注入资源。使用注释时遇到的问题@Model(adaptables = { SlingHttpServletRequest.class, Resource.class })

我得到的对象为空，而只有 Resource.Class 我得到的对象（navigationItems）。下面是我的课的片段。你能告诉我修复它的步骤吗？

import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.models.annotations.Model;
import org.apache.sling.models.annotations.Optional;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.annotation.PostConstruct;
import javax.inject.Inject;
import javax.inject.Named;
import java.util.List;

@Model(adaptables =  { SlingHttpServletRequest.class, Resource.class })
public class Header {
    private final Logger logger = LoggerFactory.getLogger(getClass());

    @Inject
    @Optional
    @Named("navitems")
    private Resource navigationItems;

    List<SiteNavigation> siteNavigationList;

    @PostConstruct
    protected void init() {
        logger.info("In init method of header model.");
        siteNavigationList = getSiteNavigationListItems(getNavigationItems());
    }

    private List<SiteNavigation> getSiteNavigationListItems(final Resource navigationItems, final Resource columnFourItems) {
        return null;
    }

    public Resource getNavigationItems() {
        return navigationItems;
    }
}

如果我删除可选注释，我会收到以下错误：

28.09.2018 14:04:39.735 *ERROR* [0:0:0:0:0:0:0:1 [1538123679033] GET /conf/myprj/settings/wcm/templates/homepage/structure.html HTTP/1.1] com.day.cq.wcm.core.impl.WCMDeveloperModeFilter Error during include of SlingRequestPathInfo: path='/conf/myprj/settings/wcm/templates/homepage/structure/jcr:content/root/header', selectorString='null', extension='html', suffix='null'
org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: Identifier com.myprj.core.models.Header cannot be correctly instantiated by the Use API
    at org.apache.sling.scripting.core.impl.DefaultSlingScript.service(DefaultSlingScript.java:510) [org.apache.sling.scripting.core:2.0.54]
    at org.apache.sling.engine.impl.request.RequestData.service(RequestData.java:552) [org.apache.sling.engine:2.6.12]

    Caused by: org.apache.sling.models.factory.MissingElementsException: Could not inject all required fields into class com.myprj.core.models.Header
    at org.apache.sling.models.impl.ModelAdapterFactory.createObject(ModelAdapterFactory.java:679) [org.apache.sling.models.impl:1.4.7.T20180205124646-b0647a3]
    at org.apache.sling.models.impl.ModelAdapterFactory.internalCreateModel(ModelAdapterFactory.java:394) [org.apache.sling.models.impl:1.4.7.T20180205124646-b0647a3]
    at org.apache.sling.models.impl.ModelAdapterFactory.createModel(ModelAdapterFactory.java:261) [org.apache.sling.models.impl:1.4.7.T20180205124646-b0647a3]
    at org.apache.sling.scripting.sightly.models.impl.SlingModelsUseProvider.provide(SlingModelsUseProvider.java:126) [org.apache.sling.scripting.sightly.models.provider:1.0.6]
    at org.apache.sling.scripting.sightly.impl.engine.extension.use.UseRuntimeExtension.call(UseRuntimeExtension.java:73) [org.apache.sling.scripting.sightly:1.0.48.1_3_1]
    ... 243 common frames omitted
    Suppressed: org.apache.sling.models.factory.MissingElementException: Could not inject private org.apache.sling.api.resource.Resource com.myprj.core.models.Header.navigationItems
        at org.apache.sling.models.impl.ModelAdapterFactory.createObject(ModelAdapterFactory.java:684) [org.apache.sling.models.impl:1.4.7.T20180205124646-b0647a3]
        ... 247 common frames omitted
    Caused by: org.apache.sling.models.factory.ModelClassException: No injector returned a non-null value!
        at org.apache.sling.models.impl.ModelAdapterFactory.injectElement(ModelAdapterFactory.java:581) [org.apache.sling.models.impl:1.4.7.T20180205124646-b0647a3]
        at org.apache.sling.models.impl.ModelAdapterFactory.createObject(ModelAdapterFactory.java:682) [org.apache.sling.models.impl:1.4.7.T20180205124646-b0647a3]
        ... 247 common frames omitted

标签： aemsling-models

解决方案

代码中的 3 个指针：

  1. 虽然 sling9 支持多种适配，但最好从SlingHttpServetlRequest 对象适配。它位于较高层并包裹大多数其他对象。
  2. 建议使您的注入器比通用 @Inject更具体。
  3. 始终指定resourceType 属性以将您的模型与特定资源类型相关联。适合片段的导出器，吊索可以关联更紧密和更好的可读性。

这将是您的吊索模型的代码：

@Model(adaptables = SlingHttpServletRequest.class, resourceType = "myprj/components/content/header",
  defaultInjectionStrategy = DefaultInjectionStrategy.OPTIONAL)
public class Header {

  @ChildResource
  private Resource navitems; // Keeping resource name and attribute name identical reduces @Named annotation

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