Java tutorial
/** * Copyright (c) Codice Foundation * * <p>This is free software: you can redistribute it and/or modify it under the terms of the GNU * Lesser General Public License as published by the Free Software Foundation, either version 3 of * the License, or any later version. * * <p>This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. A copy of the GNU Lesser General Public * License is distributed along with this program and can be found at * <http://www.gnu.org/licenses/lgpl.html>. */ package org.codice.ddf.rest.impl.action; import ddf.action.ActionProvider; import ddf.catalog.Constants; import ddf.catalog.transform.MetacardTransformer; import ddf.catalog.transformer.attribute.AttributeMetacardTransformer; import java.util.Dictionary; import java.util.HashMap; import java.util.Map; import org.apache.commons.lang.StringUtils; import org.codice.ddf.configuration.DictionaryMap; import org.osgi.framework.BundleContext; import org.osgi.framework.FrameworkUtil; import org.osgi.framework.ServiceReference; import org.osgi.framework.ServiceRegistration; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Registers {@link ActionProvider} objects into the Service Registry based upon the services * provided by other objects. * * @author Ashraf Barakat */ public class ActionProviderRegistryProxy { static final String ACTION_ID_PREFIX = "catalog.data.metacard."; private static final String PROVIDER_INTERFACE_NAME = ActionProvider.class.getName(); private static final Logger LOGGER = LoggerFactory.getLogger(ActionProviderRegistryProxy.class); private Map<ServiceReference<MetacardTransformer>, ServiceRegistration> actionProviderRegistry = new HashMap<>(); private MetacardTransformerActionProviderFactory actionFactory; public ActionProviderRegistryProxy(MetacardTransformerActionProviderFactory actionFactory) { this.actionFactory = actionFactory; } public void bind(ServiceReference<MetacardTransformer> reference) { LOGGER.info("New service registered [{}]", reference); String transformerId = null; if (reference.getProperty(Constants.SERVICE_ID) != null) { transformerId = reference.getProperty(Constants.SERVICE_ID).toString(); // backwards compatibility } if (StringUtils.isBlank(transformerId) && reference.getProperty(Constants.SERVICE_SHORTNAME) != null) { transformerId = reference.getProperty(Constants.SERVICE_SHORTNAME).toString(); } if (StringUtils.isBlank(transformerId)) { return; } String actionProviderId = ACTION_ID_PREFIX + transformerId; String attributeName = getAttributeName(reference); ActionProvider provider = actionFactory.createActionProvider(actionProviderId, transformerId, attributeName); Dictionary<String, String> actionProviderProperties = new DictionaryMap<>(); actionProviderProperties.put(Constants.SERVICE_ID, actionProviderId); ServiceRegistration actionServiceRegistration = getBundleContext().registerService(PROVIDER_INTERFACE_NAME, provider, actionProviderProperties); LOGGER.info("Registered new {} [{}]", PROVIDER_INTERFACE_NAME, actionServiceRegistration); actionProviderRegistry.put(reference, actionServiceRegistration); } public void unbind(ServiceReference<MetacardTransformer> reference) { LOGGER.info("Service unregistered [{}]", reference); ServiceRegistration actionProviderRegistration = actionProviderRegistry.remove(reference); if (actionProviderRegistration != null) { actionProviderRegistration.unregister(); LOGGER.info("Unregistered {} [{}]", PROVIDER_INTERFACE_NAME, actionProviderRegistration); } } /* Determines if this ServiceReference is an AttributeMetacardTransformer. If not returns empty string*/ private String getAttributeName(ServiceReference<MetacardTransformer> serviceReference) { if (serviceReference != null) { MetacardTransformer transformer = getBundleContext().getService(serviceReference); if (transformer instanceof AttributeMetacardTransformer) { return ((AttributeMetacardTransformer) transformer).getAttributeName(); } } return ""; } protected BundleContext getBundleContext() { return FrameworkUtil.getBundle(ActionProviderRegistryProxy.class).getBundleContext(); } }