Java tutorial
/* * #%L * ACS AEM Commons Bundle * %% * Copyright (C) 2017 - Adobe * %% * 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. * #L% */ package com.adobe.acs.commons.util; import com.adobe.acs.commons.util.mbeans.ResourceServiceManagerMBean; import com.adobe.granite.jmx.annotation.AnnotatedStandardMBean; import com.day.cq.commons.jcr.JcrConstants; import org.apache.commons.lang.ArrayUtils; import org.apache.felix.scr.annotations.Activate; import org.apache.felix.scr.annotations.Deactivate; import org.apache.sling.api.resource.LoginException; import org.apache.sling.api.resource.Resource; import org.apache.sling.api.resource.ResourceResolver; import org.osgi.framework.BundleContext; import org.osgi.framework.Constants; import org.osgi.framework.InvalidSyntaxException; import org.osgi.framework.ServiceReference; import org.osgi.framework.ServiceRegistration; import org.osgi.service.component.ComponentContext; import org.osgi.service.event.Event; import org.osgi.service.event.EventHandler; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import javax.management.NotCompliantMBeanException; import java.util.ArrayList; import java.util.HashMap; import java.util.Hashtable; import java.util.List; import java.util.Map; /** * Base class for services to extend which want to manage other services based * on repository configurations. */ public abstract class ResourceServiceManager extends AnnotatedStandardMBean implements ResourceServiceManagerMBean, EventHandler { private static final Logger log = LoggerFactory.getLogger(ResourceServiceManager.class); public static final String SERVICE_OWNER_KEY = "service.owner"; public static final String CONFIGURATION_ID_KEY = "configuration.id"; private BundleContext bctx; private Map<String, ServiceRegistration> registeredServices = new HashMap<String, ServiceRegistration>(); protected ResourceServiceManager(Class<?> mbeanInterface) throws NotCompliantMBeanException { super(mbeanInterface); } @Activate public void activate(ComponentContext context) throws LoginException { log.trace("activate"); bctx = context.getBundleContext(); refreshCache(); log.trace("Activation successful!"); } @Deactivate public void deactivate(ComponentContext context) throws LoginException { log.trace("deactivate"); for (String id : registeredServices.keySet()) { unregisterService(id); } log.trace("Deactivation successful!"); } public BundleContext getBundleContext() { return bctx; } @Override public List<String> getRegisteredConfigurations() { List<String> registeredConfigurations = new ArrayList<String>(); registeredConfigurations.addAll(this.registeredServices.keySet()); return registeredConfigurations; } public Map<String, ServiceRegistration> getRegisteredServices() { return registeredServices; } /** * Get a resource resolver to access the Sling Repository. * * @return the resource resolver */ protected abstract ResourceResolver getResourceResolver(); /** * Get the root path for the instance of the ResourceServiceManager, the * configuration should be cq:Page children of the resource at this path. * * @return the configuration root */ public abstract String getRootPath(); public void handleEvent(Event event) { log.trace("handleEvent"); refreshCache(); } /** * Checks whether or not the specified ServiceReference is up to date with * the configuration resource. * * @param config * the configuration resource * @param reference * the service reference to check * @return true if the ServiceReference is up to date with the resource, * false otherwise */ protected abstract boolean isServiceUpdated(Resource config, ServiceReference reference); @Override @SuppressWarnings({ "squid:S3776", "squid:S1141" }) public synchronized void refreshCache() { log.trace("refreshCache"); ResourceResolver resolver = null; try { resolver = getResourceResolver(); Resource aprRoot = resolver.getResource(getRootPath()); List<String> configuredIds = new ArrayList<String>(); for (Resource child : aprRoot.getChildren()) { if (!JcrConstants.JCR_CONTENT.equals(child.getName())) { log.debug("Updating service for configuration {}", child.getPath()); updateJobService(child.getPath(), child.getChild(JcrConstants.JCR_CONTENT)); configuredIds.add(child.getPath()); } } String filter = "(" + SERVICE_OWNER_KEY + "=" + getClass().getCanonicalName() + ")"; ServiceReference[] serviceReferences = (ServiceReference[]) ArrayUtils.addAll( bctx.getServiceReferences(Runnable.class.getCanonicalName(), filter), bctx.getServiceReferences(EventHandler.class.getCanonicalName(), filter)); if (serviceReferences != null && serviceReferences.length > 0) { log.debug("Found {} registered services", serviceReferences.length); for (ServiceReference reference : serviceReferences) { try { String configurationId = (String) reference.getProperty(CONFIGURATION_ID_KEY); if (!configuredIds.contains(configurationId)) { log.debug("Unregistering service for configuration {}", configurationId); this.unregisterService(configurationId); } } catch (Exception e) { log.warn("Exception unregistering reference " + reference, e); } } } else { log.debug("Did not find any registered services."); } } catch (InvalidSyntaxException e) { log.warn("Unable to search for invalid references due to invalid filter format", e); } finally { if (resolver != null) { resolver.close(); } } } @SuppressWarnings("squid:S1149") private ServiceRegistration registerService(String id, Resource config) { Hashtable<String, Object> props = new Hashtable<String, Object>(); props.put(SERVICE_OWNER_KEY, getClass().getCanonicalName()); props.put(CONFIGURATION_ID_KEY, id); ServiceRegistration serviceRegistration = registerServiceObject(config, props); registeredServices.put(id, serviceRegistration); log.debug("Automatic Package Replication job {} successfully updated with service {}", id, serviceRegistration.getReference().getProperty(Constants.SERVICE_ID)); return serviceRegistration; } /** * Register the service with the OSGi Container based on the configuration. * * @param config * the configuration resource * @param props * the default properties * @return the ServiceRegistration from registering the service */ @SuppressWarnings("squid:S1149") protected abstract ServiceRegistration registerServiceObject(Resource config, Hashtable<String, Object> props); private void unregisterService(String id) { log.debug("Unregistering job: {}", id); try { ServiceRegistration registration = registeredServices.remove(id); if (registration != null) { registration.unregister(); } log.debug("Job {} registered successfully!", id); } catch (Exception e) { log.warn("Exception unregistering job " + id, e); } } private void updateJobService(String id, Resource resource) { log.debug("Registering job: {}", id); try { String filter = "(&(" + SERVICE_OWNER_KEY + "=" + getClass().getCanonicalName() + ")" + "(" + CONFIGURATION_ID_KEY + "=" + id + "))"; ServiceReference[] serviceReferences = (ServiceReference[]) ArrayUtils.addAll( bctx.getServiceReferences(Runnable.class.getCanonicalName(), filter), bctx.getServiceReferences(EventHandler.class.getCanonicalName(), filter)); if (serviceReferences != null && serviceReferences.length > 0) { ServiceReference sr = serviceReferences[0]; if (isServiceUpdated(resource, sr)) { log.debug("Service for {} up to date, no changes necessary", id); } else { log.warn("Unbinding ServiceReference for {}", id); unregisterService(id); registerService(id, resource); } } else { registerService(id, resource); } } catch (Exception e) { log.error("Failed to register job " + id, e); } } }