Sample extension mechanism for Liferay using the OSGi capabilities

TemplateTracker.java

public class TemplateTracker implements BundleTrackerCustomizer {

  @Override
  public Object addingBundle(Bundle bundle, BundleEvent event) {
  
          // lets track all the bundles publishing the _TEMPLATES_LOCATION header
  
          String templatesLocation = bundle.getHeaders().get(_TEMPLATES_LOCATION);
  
          if (templatesLocation == null) {
                  System.out.println("No templates provided");
  
                  return bundle;
          }
  
          Enumeration<URL> templates = bundle.findEntries(
                  templatesLocation, "*.ftl", true);
  
          String context = bundle.getHeaders().get("Web-ContextPath");
  
          while (templates.hasMoreElements()) {
                  URL template = templates.nextElement();
  
                  String path = context + "_SERVLET_CONTEXT_" + template.getFile();
  
                  System.out.println("Registered template " + path);
  
                  _registeredTemplates.add(path);
          }
  
          return bundle;
  }

}