@Override public void registerContribution(Object contribution, String extensionPoint, ComponentInstance contributor) { if (THUMBNAILFACTORY_EP.equals(extensionPoint)) { ThumbnailFactoryDescriptor desc = (ThumbnailFactoryDescriptor) contribution; String docType = desc.getDocType(); if (docType != null) { factoriesByDocType.put(docType, desc.getFactory()); } String facet = desc.getFacet(); if (facet != null) { factoriesByFacets.put(facet, desc.getFactory()); } if (docType == null && facet == null) { defaultFactory = desc.getFactory(); } } else { log.error("Unknown extension point " + extensionPoint); } }