CustomClassAdapterFactory.java

import javax.jcr.Node;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.Service;
import org.apache.sling.api.adapter.AdapterFactory;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.api.resource.ResourceResolverFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 
 * @author yogeshupadhyay
 *
 */

@Component(metatype=false)
@Service (value=AdapterFactory.class)
public class CustomClassAdapterFactory implements AdapterFactory {

private static final Logger log = LoggerFactory.getLogger(CustomClassAdapterFactory.class);
private static final Class<CustomClass> YOUR_CUSTOM_CLASS = CustomClass.class;
@Reference
ResourceResolverFactory resourceResolverFactory;
@Property(name="adapters")
public static final String[] ADAPTER_CLASSES = {
YOUR_CUSTOM_CLASS.getName()
};

//This is where you define what all OOTB object it can adapt to You can also define this in //property of this component as mentioned in document above or //here http://labs.sixdimensions.com/blog/dklco/2012-05-07/new-cq-55-sling-adapters-console

@Property(name="adaptables")
    public static final String[] ADAPTABLE_CLASSES = {
            Resource.class.getName(), Node.class.getName()
};
public <AdapterType> AdapterType getAdapter(Object adaptable,Class<AdapterType> type) {
  if(adaptable instanceof Resource){
    return getAdapter((Resource) adaptable, type);
  }
  if(adaptable instanceof Node){
    return getAdapter((Node) adaptable, type);
  }
  return null;
}
/**
* Adapter for resource
* @param resource
* @param type
* @return
*/
@SuppressWarnings("unchecked")
private <AdapterType> AdapterType getAdapter(Resource resource,Class<AdapterType> type) {
  if(null == resource){
    return null;
  }
  try{
    if(type == YOUR_CUSTOM_CLASS){
      //Logic to adapt your resource to resource
      return (AdapterType) new CustomAdapter().adaptResourceToCustomClass(resource);
    }
  }catch(Exception e){
  log.error("Unable to adapt resource {}", resource.getPath());
  }
  log.error("Unable to adapt resource {}", resource.getPath());
  return null;
}
/**
* adapter for node
* @param node
* @param type
* @return
*/
@SuppressWarnings("unchecked")
private <AdapterType> AdapterType getAdapter(Node node,Class<AdapterType> type) {
  if(null == node){
    return null;
  }
  try{
    if(type == YOUR_CUSTOM_CLASS){
      return (AdapterType) new CustomAdapter().adaptNodeToCustomClass(node, this.resourceResolverFactory);
  }
  }catch(Exception e){
    log.error("Unable to adapt node to Your custom class");
  }
  log.error("Unable to adapt node");
  return null;
}
}