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NullPointerException in resolverFactory.getServiceResourceResolver(param)

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Level 2

I am trying to access page properties using services in AEM 6.4

I have created  an interface,

public interface AccessPageProp {

public String getPageProp();

}

I have created a class that implements this interface,

@Component(service = AcccessPagePropImpl.class, immediate = true)

public class AcccessPagePropImpl implements AccessPageProp {

Logger logger = LoggerFactory.getLogger(AcccessPagePropImpl.class);

@Reference

private ResourceResolverFactory resolverFactory;

@Override

public String getPageProp() {

logger.info("Entering into getPageProp()...");

String title = "";

Map<String, Object> param = new HashMap<String, Object>();

param.put(ResourceResolverFactory.SUBSERVICE, "readService");

ResourceResolver resourceResolver = null;

try {

resourceResolver = resolverFactory.getServiceResourceResolver(param);

Resource pageResource = resourceResolver.getResource("/content/MyProject/en/TestPageName/jcr:content");

Page myPage = pageResource.adaptTo(Page.class);

title = myPage.getTitle();

return title;

} catch (Exception e) {

logger.info("Exception...."+e.toString());

e.printStackTrace();

}

return title;

}

}

I am getting "java.lang.NullPointerException" in line "resourceResolver = resolverFactory.getServiceResourceResolver(param);"

11 Replies

Avatar

Level 10

What versions of scr-annotations, maven-bundle-plugin and uber-jar do you use in 6.4?

Can you check in /system/console/bundles and /components that the service is generated/active?

Check if you have assigned appropriate permissions to the "readService" against the package name of bundle.

Could you also share the stack trace?

Avatar

Level 10

Looks like you Sling Service Mapping may not have been configured properly. DId you use the Symbolic name of the OSGi bundle?

As @Gaurav Behl mentions too - ensure that your system user has the correct permissions.

I strongly recommend that you go through this HELPX Article. It will walk you through this use case on 6.4:

Adobe Experience Manager Help | Using the Sling Strongly-typed API to retrieve content from Adobe Ex...

It even uses the PageManager API.

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Level 2

I used the Symbolic name of my OSGi Bundle in user mapper service, I gave all the required permissions to my system user and I followed this article too but still I am getting Null Pointer Exception.

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Community Advisor

Can you please paste the error log here. I doubt there should be something we can figure out from the error logs itself .

PS:- Do cross verify the imports for your @Reference .

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Level 2

I used below import statement for @Reference

import org.osgi.service.component.annotations.Reference;

I used logger to print exception in my catch block like,

catch (Exception e) {

logger.info("Exception...." + e.toString());

e.printStackTrace();

}

It prints the below message,

com.myproject.core.AcccessPagePropImpl Exception....java.lang.NullPointerException

Avatar

Level 10

What versions of scr-annotations, maven-bundle-plugin and uber-jar do you use in 6.4?

Can you check in /system/console/bundles and /components that the service is generated/active?

Avatar

Community Advisor

Instead of logger.info("Exception...." + e.toString()); Could you replace + with ,  logger.info("Exception...." +, e);

This should print the entire stack trace for you.

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Level 2

My issue has been resolved when I used getSlingHelper() instead of creating a new object using new keyword in the Activate() ​method.

AccessPageProp accessPageProp = getSlingScriptHelper().getService(AccessPagePropImpl.class);

Avatar

Level 1

Hello,

I am getting the error your getting. may I know how did you resolve it?

but I have a different approach.

I am accessing "ResourceResolver resourceResolver = resolverFactory.getServiceResourceResolver(param);:

in a PostConstruct init() class.

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Community Advisor

karl515-qd9WHG

    Are your service user available for the bundle ? Do you get any error in the logs ?

Thanks

Veena

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Level 1

I already have an alternative.

by using

          SlingHttpServletRequest request;

          request.getResourceResolver().getResource(location);

But I believe I will run into that service method someday. Hope I will not get the error by then.

Thanks!