Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.apache.brooklyn.entity.stock; import java.util.ArrayList; import java.util.Collection; import java.util.List; import org.apache.brooklyn.api.entity.Entity; import org.apache.brooklyn.api.location.Location; import org.apache.brooklyn.api.mgmt.Task; import org.apache.brooklyn.core.entity.AbstractEntity; import org.apache.brooklyn.core.entity.Attributes; import org.apache.brooklyn.core.entity.Entities; import org.apache.brooklyn.core.entity.EntityPredicates; import org.apache.brooklyn.core.entity.lifecycle.Lifecycle; import org.apache.brooklyn.core.entity.lifecycle.ServiceStateLogic; import org.apache.brooklyn.core.entity.trait.Startable; import org.apache.brooklyn.core.entity.trait.StartableMethods; import org.apache.brooklyn.core.location.Locations; import org.apache.brooklyn.util.exceptions.Exceptions; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.common.base.Predicates; import com.google.common.collect.Iterables; import com.google.common.collect.Lists; public class BasicStartableImpl extends AbstractEntity implements BasicStartable { private static final Logger log = LoggerFactory.getLogger(BasicStartableImpl.class); @Override public void start(Collection<? extends Location> locations) { try { ServiceStateLogic.setExpectedState(this, Lifecycle.STARTING); addLocations(locations); locations = Locations.getLocationsCheckingAncestors(locations, this); log.info("Starting entity " + this + " at " + locations); // essentially does StartableMethods.start(this, locations), // but optionally filters locations for each child Locations.LocationsFilter filter = getConfig(LOCATIONS_FILTER); Iterable<Entity> startables = filterStartableManagedEntities(getChildren()); if (!Iterables.isEmpty(startables)) { List<Task<?>> tasks = Lists.newArrayListWithCapacity(Iterables.size(startables)); for (final Entity entity : startables) { Collection<? extends Location> l2 = locations; if (filter != null) { l2 = filter.filterForContext(new ArrayList<Location>(locations), entity); log.debug("Child " + entity + " of " + this + " being started in filtered location list: " + l2); } tasks.add(Entities.invokeEffectorWithArgs(this, entity, Startable.START, l2)); } for (Task<?> t : tasks) { t.getUnchecked(); } } sensors().set(Attributes.SERVICE_UP, true); ServiceStateLogic.setExpectedState(this, Lifecycle.RUNNING); } catch (Throwable t) { ServiceStateLogic.setExpectedState(this, Lifecycle.ON_FIRE); throw Exceptions.propagate(t); } } @Override public void stop() { ServiceStateLogic.setExpectedState(this, Lifecycle.STOPPING); sensors().set(SERVICE_UP, false); try { StartableMethods.stop(this); ServiceStateLogic.setExpectedState(this, Lifecycle.STOPPED); } catch (Exception e) { ServiceStateLogic.setExpectedState(this, Lifecycle.ON_FIRE); throw Exceptions.propagate(e); } } @Override public void restart() { StartableMethods.restart(this); } // TODO make public in StartableMethods private static Iterable<Entity> filterStartableManagedEntities(Iterable<Entity> contenders) { return Iterables.filter(contenders, Predicates.and(Predicates.instanceOf(Startable.class), EntityPredicates.isManaged())); } }