| /* |
| * Copyright (c) 2010, Rickard Öberg. All Rights Reserved. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| package org.qi4j.api.service.importer; |
| |
| import org.qi4j.api.injection.scope.Structure; |
| import org.qi4j.api.service.ImportedServiceDescriptor; |
| import org.qi4j.api.service.ServiceFinder; |
| import org.qi4j.api.service.ServiceImporter; |
| import org.qi4j.api.service.ServiceImporterException; |
| import org.qi4j.api.service.ServiceReference; |
| |
| /** |
| * Use a registered service that implements ServiceImporter to do the actual |
| * import. The service id of the service that this importer should delegate to must |
| * be set as meta-info on this service. Example: |
| * <pre><code> |
| * module.services(MyServiceImporterService.class).identifiedBy("someid"); |
| * module.importedServices(OtherService.class).importedBy(ServiceInstanceImporter.class).setMetaInfo("someid"); |
| * </code></pre> |
| */ |
| public class ServiceInstanceImporter<T> |
| implements ServiceImporter<T> |
| { |
| @Structure |
| ServiceFinder finder; |
| |
| ServiceImporter<T> service; |
| |
| String serviceId; |
| |
| @Override |
| public T importService( ImportedServiceDescriptor importedServiceDescriptor ) |
| throws ServiceImporterException |
| { |
| serviceId = importedServiceDescriptor.metaInfo( String.class ); |
| |
| return serviceImporter().importService( importedServiceDescriptor ); |
| } |
| |
| @Override |
| public boolean isAvailable( T instance ) |
| { |
| return serviceImporter().isAvailable( instance ); |
| } |
| |
| @SuppressWarnings( {"raw", "unchecked"} ) |
| private ServiceImporter<T> serviceImporter() |
| { |
| if( service == null ) |
| { |
| for( ServiceReference<ServiceImporter> reference : finder.<ServiceImporter>findServices( ServiceImporter.class ) ) |
| { |
| if( reference.identity().equals( serviceId ) ) |
| { |
| service = reference.get(); |
| break; |
| } |
| } |
| } |
| |
| if( service == null ) |
| { |
| throw new ServiceImporterException( "No service importer with id '" + serviceId + "' was found" ); |
| } |
| |
| return service; |
| } |
| } |