AEM6.4 @Reference not working in SlingServlet

[pradeepdubey82]

Hi  All,

My sling servlet is not working as soon as i add

@Reference in it, otherwise it works fine

Below is the servlet code, i have create custom configuration as per the AEM6.4 standards(one @Interface class, one Interface class, one Impl class with proper annotations(org.osgi.service.component.annotations))

@Component(service = Servlet.class,

property = { Constants.SERVICE_DESCRIPTION + "=Simple Demo Servlet",

"sling.servlet.methods=" + HttpConstants.METHOD_GET,

"sling.servlet.paths=" + "/bin/testservlet" }

)

public class TestServlet extends SlingAllMethodsServlet {

  private static final long serialVersionUID = 1L;

  @Reference

  MySimpleService mySimpleService;

  private static final Logger logger =

  LoggerFactory.getLogger(TestServlet.class);

  @Override

  protected void doGet(final SlingHttpServletRequest req, final

  SlingHttpServletResponse resp) throws ServletException, IOException {

  logger.info("Inside doGet!!!");

  try {

  logger.info("Name ::: "+mySimpleService.getMyName());

  resp.getWriter().write(mySimpleService.getMyName()); }

  catch(Exception ex) {

  logger.error("Error in  doGet ::: ", ex);

  }

  }

}

Please advise, any help is highly appreciated.

Thanks,

Pradeep

[smacdonald2008]

Do you mean when you have this line of code:

@Reference

  MySimpleService mySimpleService;

Its not working?

[arunpatidar]

Hi,

Could you please check if your bundle is active or not? If yes the check if you using osgi reference annotation. e.g.

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

e.g.

aem63app-repo/GetFeaturesServlet.java at master · arunpatidar02/aem63app-repo · GitHub

[pradeepdubey82]

Yes, If I add @Reference sling servlet stopped working. It is in unsatisfied state due to the reference.

[pradeepdubey82]

Yes, My bundle is in active state, and servlet is unsatisfied state due to @Reference

[Hemant_arora]

In your service class MySimpleService  check the @component annotation:

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

Go to http://localhost:4502/system/console/components and search for MySimpleService . Check the status of the service.

[pradeepdubey82]

Hi Donald,

Below is my entire code

import org.osgi.service.metatype.annotations.AttributeDefinition;

import org.osgi.service.metatype.annotations.ObjectClassDefinition;

@ObjectClassDefinition(name = "My Service Configuration", description = "Service Configuration")

public @interface CustomConfigIntf {

@AttributeDefinition(name = "Test Namel", defaultValue="Pradeep", description = "Read my name")

    String name();

}

public interface MySimpleService {

public String getName();

}

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

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

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

import org.osgi.service.metatype.annotations.Designate;

@Component(service=MySimpleService.class, configurationPolicy=ConfigurationPolicy.REQUIRE)

@Designate(ocd = CustomConfigIntf.class)

public class MySimpleServiceImpl implements MySimpleService {

private CustomConfigIntf config;

    private String name;

    @Activate

    public void activate(CustomConfigIntf config) {

        this.config = config;

        this.name = config.name();

    }

    public String getName() {

        return this.name;

    }

}

Let me know where i am doing wrong?

@Referencce is not working in servlet.

Thanks,

Pradeep

[Hemant_arora]

This should work.

____________________________________________________________________________________________________

import org.osgi.service.metatype.annotations.AttributeDefinition;

import org.osgi.service.metatype.annotations.ObjectClassDefinition;

@ObjectClassDefinition(name = "My Service Configuration", description = "Service Configuration")

public @interface CustomConfigIntf {

@AttributeDefinition(name = "Test Namel", defaultValue="Pradeep", description = "Read my name")

    String name();

}

______________________________________________________________________________________________________

public interface MySimpleService {

public String getName();

}

______________________________________________________________________________________________________

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

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

import org.osgi.service.metatype.annotations.Designate;

import com.aem.test.core.CustomConfigIntf;

import com.aem.test.core.service.MySimpleService;

@Component(service=MySimpleService.class, configurationPolicy=ConfigurationPolicy.REQUIRE)

@Designate(ocd = CustomConfigIntf.class)

public class MySimpleServiceImpl implements MySimpleService {

private CustomConfigIntf configs;

@Activate

public void activate(CustomConfigIntf config) {

this.configs = config;

}

public String getName() {

return configs.name();

}

}

[smacdonald2008]

See this article - where we used @Reference in a SLing Servlet:

Adobe Experience Manager Help | Querying Adobe Experience Manager 6.4 JCR data using the QueryBuilde...

[pradeepdubey82]

Hi Donald,

My requirement is to read custom configuration properties from osgi console in sling servlet using AEM6.4 SP2.

The example you shared is just to define and use the class in @Reference. I didn't find any custom configuration.

Thanks,

Pradeep

[pradeepdubey82]

Hi Hemant arora tried your way also, didn't work.

[smacdonald2008]

That may be where your issue is. I would not try to mix that up.

I would create a separate class that reads those OSGi conig values. Then from your Sling Servlet - you can create an instance of that class and invoke a method to get the config values.

[smacdonald2008]

Following article shows how to read OSGi config values - notice this class is not a Sling Servlet:

Reading OSGi Configuration Values for Adobe Experience Manager 6.3

[pradeepdubey82]

I followed the same link, not working in  sling servlet.

[smacdonald2008]

Like I said - create the logic to read OSGI config values in a separate class. Then create an instance of that class in the servlet and call a getter method. That will return config values in the servlet.

[pradeepdubey82]

Hi  Donald,

In AEM 6.4 There is a entirely different approach to read config values. That i am trying to understand how to implement it.

[smacdonald2008 · Accepted solution]

Look at our SOLR Article. This one closely matches your requirement. We have a class named MySimpleService that reads OSGi config values.

In the Servlet in this article - we use a @Refence to get config values:

@Reference

    SolrServerConfiguration solrConfigurationService;

This shows the proper way of getting OSGI configuration information within an AEM Servlet. Never try and read OSGI config information directly from a servlet. Write a separate class - as shown in this development article.

Adobe Experience Manager Help | Integrating SOLR with Adobe Experience Manager 6.4

Hope this clear this issue up. Notice the Java code in this Servlet. We use the CONFIG values to perform SOLR actions - such as getting the URL to the SOLR server.

            final String protocol = solrConfigurationService.getSolrProtocol();

        final String serverName = solrConfigurationService.getSolrServerName();

        final String serverPort = solrConfigurationService.getSolrServerPort();

        final String coreName = solrConfigurationService.getSolrCoreName();

        final String pagesResourcePath = solrConfigurationService

I would go through this entire article so you understand.

Hope this helps you.

[pradeepdubey82]

Hi Donald,

No luck,  same error,  servlet is in unsatisfied state.

[smacdonald2008]

Go through this article -- follow it step by step - it works. Then once you get it working - you can compare it with yours to see the difference.

[arunpatidar]

Hi,

Can you try with below code, I tried changing with your config , other code is almost same except method name.

------------------------------------- CustomConfigIntf

import org.osgi.service.metatype.annotations.AttributeDefinition;

import org.osgi.service.metatype.annotations.AttributeType;

import org.osgi.service.metatype.annotations.ObjectClassDefinition;

@ObjectClassDefinition(name = "My Service Configuration", description = "Service Configuration")

public @interface CustomConfigIntf {

@AttributeDefinition(

        name = "TestName",

        description = "Read my Name",

        type = AttributeType.STRING

    )

String getName() default "Pradeep";

}

---------------------- MyCustomeService

public interface MyCustomeService {

public String getMyName();

}

-------------------------- MyCustomeServiceImpl

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

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

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

import org.osgi.service.metatype.annotations.Designate;

import com.acc.arch17.core.services.CustomConfigIntf;

import com.acc.arch17.core.services.MyCustomeService;

@Component(service = MyCustomeService.class, configurationPolicy = ConfigurationPolicy.REQUIRE)

@Designate(ocd = CustomConfigIntf.class)

public class MyCustomeServiceImpl implements MyCustomeService {

private CustomConfigIntf config;

private String name;

@Activate

public void activate(CustomConfigIntf config) {

this.config = config;

this.name = config.getName();

}

public String getMyName() {

return this.name;

}

}

--------------------------------------- TestServlet

import java.io.IOException;

import javax.servlet.Servlet;

import javax.servlet.ServletException;

import org.apache.sling.api.SlingHttpServletRequest;

import org.apache.sling.api.SlingHttpServletResponse;

import org.apache.sling.api.servlets.HttpConstants;

import org.apache.sling.api.servlets.SlingAllMethodsServlet;

import org.osgi.framework.Constants;

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

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

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import com.acc.arch17.core.services.MyCustomeService;

@Component(service = Servlet.class, property = { Constants.SERVICE_DESCRIPTION + "=Simple Demo Servlet",

"sling.servlet.methods=" + HttpConstants.METHOD_GET, "sling.servlet.paths=" + "/bin/testservlet" })

public class TestServlet extends SlingAllMethodsServlet {

private static final long serialVersionUID = 1L;

@Reference

MyCustomeService myCustomService;

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

@Override

protected void doGet(final SlingHttpServletRequest req, final SlingHttpServletResponse resp)

throws ServletException, IOException {

logger.info("Inside doGet!!!");

try {

logger.info("Name ::: " + myCustomService.getMyName());

resp.getWriter().write(myCustomService.getMyName());

} catch (Exception ex) {

logger.error("Error in  doGet ::: ", ex);

} finally {

resp.getWriter().close();

}

}

}

output

[SanketJa1]

@arunpatidar 

I copy pasted your entire code which you have given above but still I'm getting the error for the @Reference same error I was getting for my code as well.