ResourceResolverFactory在服务中为空，在Sling模型类中抛出LoginException

Question

1)我试图像这样在ResourceResolverFactory类中注入SlingModel：

package com.aem.sites.models;

import java.util.HashMap;
import java.util.Map;

import javax.annotation.PostConstruct;
import javax.inject.Inject;
import javax.inject.Named;

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

import com.aem.sites.services.WeatherService;


@Model(adaptables=Resource.class)
public class Banner {

    final static Logger logger = LoggerFactory.getLogger(Banner.class);

    @Inject
    private WeatherService weatherService;

    private String serviceEndpoint;

    private String apiKey;

    private String temperature;

    @Inject
    @Optional
    @Named("bannerText")
    private String bannerText;

    @Inject
    @Optional
    @Named("button1Text")
    private String button1Text;

    @Inject
    @Optional
    @Named("button2Text")
    private String button2Text;

     @Inject
    private ResourceResolverFactory resourceResolverFactory;

        @PostConstruct
        public void init() {
            serviceEndpoint = weatherService.getServiceEndpoint();
            apiKey = weatherService.getApiKey();
            temperature = weatherService.getTemperatureValue()+" "+weatherService.getUnit();
            checkTemperatureProperty();
        }


        public String getServiceEndpoint() {
            return serviceEndpoint;
        }

        public String getApiKey() {
            return apiKey;
        }


        public String getTemperature() {
            return temperature;
        }


        public String getBannerText() {
            return bannerText;
        }


        public String getButton1Text() {
            return button1Text;
        }


        public String getButton2Text() {
            return button2Text;
        }

        private void checkTemperatureProperty() {
            logger.info("**********************checkTemperatureProperty****************");
            Map<String, Object> param = new HashMap<String, Object>();
            param.put(ResourceResolverFactory.SUBSERVICE,"getResourceResolver");
            ResourceResolver resourceResolver = null;
            try {
                if(resourceResolverFactory == null) {
                    logger.info("***********************resourceResolverFactory is null******************************");
                }
                else {
                    resourceResolver = resourceResolverFactory.getServiceResourceResolver(param);
                    logger.info("**********************resource resolver id****************"+resourceResolver.getUserID());
                    //Resource resource = resourceResolver.getResource("/content/aemsite/en/jcr:content/root/responsivegrid/banner");
                    //ValueMap readMap = resource.getValueMap();
                    //logger.info(readMap.get("temperature", ""));
                }
            }
            catch (LoginException e) {
                logger.error("LoginException",e);
            } finally{
                if(resourceResolver != null && resourceResolver.isLive()){
                    resourceResolver.close();
                }
            }
        }

}

这里讨论的方法是checkTemperatureProperty()。我创建了如下所示的系统用户：

​

​

我还配置了Mapper服务修正案如下：

​

​

包的符号名如下所示：

​

​

ResourceResolverFactor注入在Sling Model类中抛出LoginException，下面是错误：

com.aem.sites.models.Banner LoginException
org.apache.sling.api.resource.LoginException: Cannot derive user name for bundle org.apache.sling.models.impl [489] and sub service getResourceResolver
    at org.apache.sling.resourceresolver.impl.ResourceResolverFactoryImpl.getServiceResourceResolver(ResourceResolverFactoryImpl.java:86)

当我试图使用@Reference在服务中使用ResourceResolverFactory时，它将抛出一个空指针异常。

下面给出了所讨论的类，方法checkTemperatureProperty()行号195：

package com.aem.sites.services.impl;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.lang.StringUtils;
import org.apache.felix.scr.annotations.Reference;
import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.osgi.service.component.annotations.Activate;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Deactivate;
import org.osgi.service.component.annotations.Modified;
import org.osgi.service.metatype.annotations.Designate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.aem.sites.interfaces.Configuration;
import com.aem.sites.pojos.CurrentConditions;
import com.aem.sites.services.WeatherService;
import com.google.gson.Gson;

import org.apache.sling.api.resource.Resource;
import org.apache.sling.api.resource.ResourceResolver;
import org.apache.sling.api.resource.ResourceResolverFactory;
import org.apache.sling.api.resource.ValueMap;
import org.apache.sling.api.resource.LoginException;


// TODO: Auto-generated Javadoc
/**
 * The Class WeatherServiceImpl.
 */
@Component(service = WeatherService.class,
immediate = true,
configurationPid = "com.aem.sites.services.impl.WeatherServiceImpl")
@Designate(ocd = Configuration.class)
public class WeatherServiceImpl implements WeatherService {

    /** The Constant logger. */
    final static Logger logger = LoggerFactory.getLogger(WeatherServiceImpl.class);

    /** The service endpoint. */
    private String serviceEndpoint;

    /** The api key. */
    private String apiKey;

    /** The response body. */
    private String responseBody;

    /** The temperature value. */
    private String temperatureValue;

    /** The unit. */
    private String unit;

    /** The resource resolver factory. */
    @Reference
    private ResourceResolverFactory resourceResolverFactory;

    /* (non-Javadoc)
     * @see com.aem.sites.services.WeatherService#getServiceEndpoint()
     */
    @Override
    public String getServiceEndpoint() {
        return serviceEndpoint;
    }

    /* (non-Javadoc)
     * @see com.aem.sites.services.WeatherService#getApiKey()
     */
    @Override
    public String getApiKey() {
        return apiKey;
    }

    /**
     * Activate.
     *
     * @param config the config
     */
    @Activate
    @Modified
    protected final void activate(Configuration config) {
        logger.info("**********************************************activate********************************************");
        serviceEndpoint = config.getServiceURL();
        apiKey = config.getApiKey();
        String serviceURL = createRequestURL();
        logger.info("**************************The serviceURL is*******************************************"+serviceURL);
        callWebService(serviceURL);
        String responseString = getResponseBody();
        logger.info("**************************The response body is*******************************************"+responseString);
        convertStringToPojos(responseString);
        checkTemperatureProperty();
        //saveTemperatureInTheNode();

    }

    /**
     * Creates the request URL.
     *
     * @return the string
     */
    private String createRequestURL() {
        StringBuilder sb = new StringBuilder(); ;
        if(!StringUtils.isEmpty(serviceEndpoint)) {
            sb.append(serviceEndpoint);
            sb.append("/currentconditions/v1/33785");
            sb.append("?apikey=");
            sb.append(apiKey);
        }
        return sb.toString();
    }

    /**
     * Call web service.
     *
     * @param serviceURL the service URL
     */
    private void callWebService(String serviceURL) {
        if(!StringUtils.isEmpty(serviceURL))  {
            CloseableHttpClient httpclient = HttpClients.createDefault();
            HttpGet httpget = new HttpGet(serviceURL);
            CloseableHttpResponse response = null;
            try {
                response = httpclient.execute(httpget);
                HttpEntity entity = response.getEntity();
                int status = response.getStatusLine().getStatusCode();
                if (status >= 200 && status < 300) {
                    if (entity != null) {
                        String responseString = EntityUtils.toString(entity);
                        setResponseBody(responseString);
                    }
                }
                else {
                    logger.info("*********************Unexpected response status: " + status);
                }
            } catch (IOException | UnsupportedOperationException e) {
                // TODO Auto-generated catch block
                logger.info("***********************************inside catch block****************IOException"+e.getMessage());
            }
            finally {
                if(null != response){
                    try {
                        response.close();
                        httpclient.close();
                    } catch (IOException e) {
                        logger.info("***********************************inside finally block****************IOException"+e.getMessage());
                    }
                }
            }
        }
    }

    /**
     * Convert string to pojos.
     *
     * @param jsonString the json string
     */
    private void convertStringToPojos(String jsonString) {
        if(!StringUtils.isEmpty(jsonString))  {
            jsonString = jsonString.substring(1);
            if(!StringUtils.isEmpty(jsonString))  {
                int ind = jsonString.lastIndexOf("]");
                if(ind >= 0) {
                    jsonString = jsonString.substring(0,jsonString.length()-1);
                }
                Gson gson = new Gson();
                if(!StringUtils.isEmpty(jsonString))  {
                    CurrentConditions conditions = gson.fromJson(jsonString, CurrentConditions.class);
                    logger.info("***************current temperature is*****************"+conditions.getTemperature().getImperial().getValue());
                    temperatureValue = conditions.getTemperature().getImperial().getValue();
                    unit = conditions.getTemperature().getImperial().getUnit();
                }
            }
        }
    }


    /**
     * Save temperature in the node.
     */
    private void checkTemperatureProperty() {
        logger.info("**********************checkTemperatureProperty****************");
        Map<String, Object> param = new HashMap<String, Object>();
        param.put(ResourceResolverFactory.SUBSERVICE,"getResourceResolver");
        ResourceResolver resourceResolver = null;
        try {
            resourceResolver = resourceResolverFactory.getServiceResourceResolver(param);
            logger.info("**********************resource resolver id****************"+resourceResolver.getUserID());
            Resource resource = resourceResolver.getResource("/content/aemsite/en/jcr:content/root/responsivegrid/banner");
            ValueMap readMap = resource.getValueMap();
            logger.info(readMap.get("temperature", ""));
        }
        catch (LoginException e) {
            logger.error("LoginException",e);
        } finally{
            if(resourceResolver != null && resourceResolver.isLive()){
                resourceResolver.close();
            }
        }
    }

    private void saveTemperatureProperty() {

    }

    /**
     * Gets the response body.
     *
     * @return the response body
     */
    public String getResponseBody() {
        return responseBody;
    }

    /**
     * Sets the response body.
     *
     * @param responseBody the new response body
     */
    public void setResponseBody(String responseBody) {
        this.responseBody = responseBody;
    }

    /* (non-Javadoc)
     * @see com.aem.sites.services.WeatherService#getTemperatureValue()
     */
    @Override
    public String getTemperatureValue() {
        // TODO Auto-generated method stub
        return temperatureValue;
    }

    /* (non-Javadoc)
     * @see com.aem.sites.services.WeatherService#getUnit()
     */
    @Override
    public String getUnit() {
        // TODO Auto-generated method stub
        return unit;
    }

    /**
     * Deactivate.
     */
    @Deactivate
    protected void deactivate() {
    }
}

我首先尝试在服务类(第二类)中使用ResourceResolverFactory，然后在Banner.java(第一类)中使用。但在这两种情况下都没有用。

我已经阅读了各种教程，以及在这里提出的关于堆栈溢出的类似问题。其中一些人在这里：

ResourceResolverFactory getServiceResourceResolver在AEM6.1中抛出异常

服务类中的ResourceResolverFactory和SlingRepository null

ResourceResolverFactory为NULL (Adobe )

完全跟着它，但却找不到决议。任何帮助都是非常感谢的。

提前谢谢。

Answer 1

我看到您正在使用OSGI声明性服务(DS)。

有几件事：

1. 如果您是而不是使用SCR注释的，则应该从POM/s中删除SCR依赖项以消除混淆。
2. 如果您只使用OSGI，则必须具有以下内容：
   • 阅读Nate的优秀帖子
   • 您的maven-bundle-plugin依赖项必须是版本3.2.0或更高版本。
   • 您必须在包org.osgi.service.component.annotations和中使用注释，而不是在org.apache.felix.scr.annotations.Reference包中使用SCR注释。

​

在您的气象服务中，我看到您使用的是SCR的@Reference，而不是OSGI的@Reference

吊索模型中的：您应该为服务使用OSGI服务注入器：@OSGiService虽然使用@Inject工作得很好，但特定的注入器对可读性和性能更好，尽管性能不高，因为我们只使用特定的注入器。

这里是一个使用您的代码的服务示例：

气象服务界面：

package com.aem.sites.services;

public interface WeatherService
{
  public String checkApps();

}

气象服务推动：

package com.aem.sites.services.impl;

import java.util.HashMap;
import java.util.Map;

import org.apache.felix.scr.annotations.Reference;
import org.osgi.service.component.annotations.Activate;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Deactivate;
import org.osgi.service.component.annotations.Modified;
import org.osgi.service.metatype.annotations.Designate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.aem.sites.services.Configuration;
import com.aem.sites.services.WeatherService;

import org.apache.sling.api.resource.Resource;
import org.apache.sling.api.resource.ResourceResolver;
import org.apache.sling.api.resource.ResourceResolverFactory;
import org.apache.sling.api.resource.LoginException;



/**
 * The Class WeatherServiceImpl.
 */
@Component(service = WeatherService.class,
        immediate = true,
        configurationPid = "com.aem.sites.services.impl.WeatherServiceImpl")
@Designate(ocd = Configuration.class)
public class WeatherServiceImpl implements WeatherService {

  /** The Constant logger. */
  final static Logger logger = LoggerFactory.getLogger(WeatherServiceImpl.class);


  /** The resource resolver factory. */
  @Reference
  private ResourceResolverFactory resourceResolverFactory;

  private ResourceResolver resolver;


  /**
   * Activate.
   *
   * @param config the config
   */
  @Activate
  @Modified
  protected final void activate(Configuration config) {}



  /**
   * check if we can get /apps resource, print weather it's null or not
   */
  public String checkApps() {
    logger.info("*************** checkApps");
    Map<String, Object> param = new HashMap<String, Object>();
    param.put(ResourceResolverFactory.SUBSERVICE,"getResourceResolver");
    ResourceResolver resourceResolver = null;
    try
    {
      resourceResolver = resourceResolverFactory.getServiceResourceResolver(param);
      logger.info("*************** resource resolver user id: "+resourceResolver.getUserID());
      Resource appsResource = resourceResolver.getResource("/apps");

      // return appropriate msg
      return appsResource == null
             ? "apps resource is null"
             : "apps resource is NOT null";

    }
    catch (LoginException e)
    {
      logger.error("LoginException",e);
      return e.toString();
    }
    finally
    {
      if(resourceResolver != null && resourceResolver.isLive()){
        resourceResolver.close();
      }
    }

  }
  /**
   * Deactivate.
   */
  @Deactivate
  protected void deactivate() {
  }
}

横幅模型：

package com.aem.sites.models;

import javax.annotation.PostConstruct;

import org.apache.sling.api.resource.Resource;
import org.apache.sling.models.annotations.Model;
import org.apache.sling.models.annotations.injectorspecific.OSGiService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.aem.sites.services.WeatherService;


@Model(adaptables=Resource.class)
public class Banner {

  final static Logger logger = LoggerFactory.getLogger(Banner.class);

  @OSGiService
  private WeatherService weatherService;

  private String msg;

  @PostConstruct
  public void init() {
    msg = weatherService.checkApps();
  }

  public String getMsg() {
    return msg;
  }

}

显示msg的简单组件：

<h1 data-sly-use.banner="com.aem.sites.models.Banner">${banner.msg}</h1>

更新:关于resourceResolver在吊索模型中的使用：

最好将逻辑保持在单独的服务中，而不使用模型的资源/资源解析器。在您的代码中，Banner#checkTemperatureProperty应该在服务中而不是在模型本身中。

这是我个人的观点，这里没有对错：

您始终可以通过注入resourceResolver模型或通过注入资源或请求来获取吊带模型中的解析器，然后从资源/请求中获取解析器。在任何一种情况下，您都会得到一个与请求用户具有相同权限的resourceResolver，这对于组件来说是首选的。例如，如果您需要从同一页面上的不同组件或一般的/content中获取一个资源，这就是方法。

如果您有一个需要执行操作的用例--请求用户或匿名用户没有足够的权限来执行，也不想为其授予权限，则可以通过具有足够权限的系统用户获得resourceResolver。例如，您希望从/apps读取一些属性，或者您希望启动一个工作流.在这种情况下，将这些代码保存在服务中而不是模型本身中更有组织，并且可能会对其进行泛化，以便在其他模型中重用它。