AEM 6.3 Using OSGi R6 Annotations and Sling Models

Question

I am trying to create an OSGi Service using OSGi R6 annotations and then injecting it in the Sling Model class like this:

   package com.aem.sites.models;

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

import org.apache.sling.api.resource.Resource;
import org.apache.sling.models.annotations.Model;
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 message;

        @PostConstruct
        public void init() {
            logger.info("##############################################################calling the init method");
            message = weatherService.getName();
        }

        public String getMessage() {
            logger.info("##############################################################inside the get message method");
            return message;
        }

}

The OSGi configuration interface looks like this:

    package com.aem.sites.interfaces;

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

@ObjectClassDefinition(name = "Configuration", description = "Configuration file")
public @interface Configuration {

     @AttributeDefinition(
                name = "String Property",
                description = "Sample String property",
                type = AttributeType.STRING
            )
     public String getText() default "It's a test";
}

and the service class looks like this:

   package com.aem.sites.services.impl;


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.component.annotations.ConfigurationPolicy;
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.services.WeatherService;

@Component(service=WeatherService.class,
immediate=true,
configurationPid = "com.aem.sites.services.impl.WeatherServiceImpl",
configurationPolicy=ConfigurationPolicy.REQUIRE
)
@Designate(ocd = Configuration.class)
public class WeatherServiceImpl implements WeatherService{

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

    private Configuration config;

    private String name;

    @Activate
    @Modified
    protected final void activate(Configuration configuration) {
        logger.info("##############################################################calling activate method inside the weather service impl class");
        this.config = configuration;
        name = config.getText();
    }

    @Deactivate
    protected void deactivate() {
    }

    @Override
    public String getName() {
        logger.info("##############################################################calling get name method inside the weather service impl class");
        return name;
    }
}

and finally the service interface:

package com.aem.sites.services;

public interface WeatherService {

    public String getName();

}

I am trying to use the Sling Model Pojo in the HTL class like this:

<sly data-sly-use.banner="com.aem.sites.models.Banner">

    <div class="inner">
        <h2>${banner.message}</h2

    </div>

</sly>

But I am not able to see any texts. I have used the logger.info but can't see it in the log files either. I am sure I am doing something very wrong here but unable to locate since I have just started playing with OSGi R6 annotations and Sling Models. Any help is appreciated.

Adding Maven dependencies:

Parent pom.xml

<!-- <plugin>
                    <groupId>org.apache.felix</groupId>
                    <artifactId>maven-bundle-plugin</artifactId>
                    <version>2.5.3</version>
                </plugin>  -->             
                <plugin>
                      <groupId>org.apache.felix</groupId>
                      <artifactId>maven-bundle-plugin</artifactId>
                      <version>3.3.0</version>
                      <inherited>true</inherited>
                </plugin>

<dependency>
              <groupId>org.osgi</groupId>
              <artifactId>org.osgi.service.component.annotations</artifactId>
              <version>1.3.0</version>
               <scope>compile</scope>
            </dependency>

            <dependency>
              <groupId>org.osgi</groupId>
              <artifactId>org.osgi.annotation</artifactId>
              <version>6.0.0</version>
            </dependency>

            <dependency>
              <groupId>org.osgi</groupId>
              <artifactId>org.osgi.service.metatype.annotations</artifactId>
              <version>1.3.0</version>
            </dependency>

Core pom.xml

<dependency>
              <groupId>org.osgi</groupId>
              <artifactId>org.osgi.service.component.annotations</artifactId>
            </dependency>
            <dependency>
              <groupId>org.osgi</groupId>
              <artifactId>org.osgi.annotation</artifactId>
            </dependency>
            <dependency>
              <groupId>org.osgi</groupId>
              <artifactId>org.osgi.service.metatype.annotations</artifactId>
            </dependency>

<plugin>
                <groupId>org.apache.felix</groupId>
                <artifactId>maven-bundle-plugin</artifactId>
                <extensions>true</extensions>
                <configuration>
                    <instructions>
                        <Bundle-SymbolicName>com.aem.site.aem-site</Bundle-SymbolicName>
                        <Sling-Model-Packages>
                          com.aem.sites.models
                        </Sling-Model-Packages>
                         <Import-Package>javax.inject;version=0.0.0,*</Import-Package>
                    </instructions>
                </configuration>
            </plugin>   

Answer 1

In order to make the Sling Models available you have to properly configure <Sling-Model-Packages> section of the maven-bundle-plugin, see https://sling.apache.org/documentation/bundles/models.html#basic-usage

You can check the models are properly exposed by using the Sling Models Web Console: http://localhost:4502/system/console/status-slingmodels

Answer 2

In the service impl you have put service=WeatherServiceImpl.class which is incorrect, it should be the service interface name.

so, in WeatherServiceImpl change

 @Component(service=WeatherServiceImpl.class,

to

 @Component(service=WeatherService.class,

..

EDIT: also configurationPolicy=ConfigurationPolicy.REQUIRE means that there should be at least one config in order for the DS component to be active. (config from code wont work)

so you can go to system /system/console/configMgr/com.aem.sites.services.impl.WeatherServiceImpl and put a value and save. or you can set configurationPolicy to optional and your code will work without config.