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.group; import static org.apache.brooklyn.util.groovy.GroovyJavaMethods.elvis; import static org.apache.brooklyn.util.groovy.GroovyJavaMethods.truth; import java.util.Arrays; import java.util.Collection; import java.util.List; import java.util.Map; import java.util.concurrent.ExecutionException; import org.apache.brooklyn.api.entity.Entity; import org.apache.brooklyn.api.entity.EntityLocal; import org.apache.brooklyn.api.entity.EntitySpec; import org.apache.brooklyn.api.location.Location; import org.apache.brooklyn.api.mgmt.Task; import org.apache.brooklyn.core.effector.Effectors; import org.apache.brooklyn.core.entity.Entities; import org.apache.brooklyn.core.entity.EntityInternal; import org.apache.brooklyn.core.entity.factory.EntityFactory; import org.apache.brooklyn.core.entity.factory.EntityFactoryForLocation; import org.apache.brooklyn.core.entity.lifecycle.Lifecycle; import org.apache.brooklyn.core.entity.lifecycle.ServiceStateLogic; import org.apache.brooklyn.core.entity.trait.Changeable; import org.apache.brooklyn.core.entity.trait.Startable; import org.apache.brooklyn.core.location.Locations; import org.apache.brooklyn.enricher.stock.Enrichers; import org.apache.brooklyn.util.collections.MutableList; import org.apache.brooklyn.util.exceptions.Exceptions; import org.apache.brooklyn.util.groovy.GroovyJavaMethods; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.common.base.Preconditions; import com.google.common.base.Predicates; import com.google.common.base.Throwables; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableMap; import com.google.common.collect.Iterables; import com.google.common.collect.Maps; /** * When a dynamic fabric is started, it starts an entity in each of its locations. * This entity will be the parent of each of the started entities. */ public class DynamicFabricImpl extends AbstractGroupImpl implements DynamicFabric { private static final Logger logger = LoggerFactory.getLogger(DynamicFabricImpl.class); public DynamicFabricImpl() { } @Override public void init() { super.init(); enrichers().add(Enrichers.builder().aggregating(Changeable.GROUP_SIZE).publishing(FABRIC_SIZE).fromMembers() .computingSum().valueToReportIfNoSensors(0).build()); sensors().set(SERVICE_UP, false); } protected EntitySpec<?> getMemberSpec() { return getConfig(MEMBER_SPEC); } protected EntityFactory<?> getFactory() { return getConfig(FACTORY); } protected String getDisplayNamePrefix() { return getConfig(DISPLAY_NAME_PREFIX); } protected String getDisplayNameSuffix() { return getConfig(DISPLAY_NAME_SUFFIX); } @Override public void setMemberSpec(EntitySpec<?> memberSpec) { setConfigEvenIfOwned(MEMBER_SPEC, memberSpec); } @Override public void setFactory(EntityFactory<?> factory) { setConfigEvenIfOwned(FACTORY, factory); } @Override public void start(Collection<? extends Location> locsO) { addLocations(locsO); List<Location> locationsToStart = MutableList.copyOf(Locations.getLocationsCheckingAncestors(locsO, this)); Preconditions.checkNotNull(locationsToStart, "locations must be supplied"); Preconditions.checkArgument(locationsToStart.size() >= 1, "One or more locations must be supplied"); int locIndex = 0; ServiceStateLogic.setExpectedState(this, Lifecycle.STARTING); try { Map<Entity, Task<?>> tasks = Maps.newLinkedHashMap(); // first look at existing Startable children - start them with the locations passed in here, // if they have no locations yet for (Entity child : getChildren()) { if (child instanceof Startable) { addMember(child); Location it = null; if (child.getLocations().isEmpty()) // give him any of these locations if he has none, allowing round robin here if (!locationsToStart.isEmpty()) { it = locationsToStart.get(locIndex++ % locationsToStart.size()); ((EntityInternal) child).addLocations(Arrays.asList(it)); } tasks.put(child, Entities.submit(this, Effectors .invocation(child, START, ImmutableMap.of("locations", it == null ? ImmutableList.of() : ImmutableList.of(it))) .asTask())); } } // remove all the locations we applied to existing nodes while (locIndex-- > 0 && !locationsToStart.isEmpty()) locationsToStart.remove(0); // finally (and usually) we create new entities for locations passed in // (unless they were consumed by pre-existing children which didn't have locations) for (Location it : locationsToStart) { Entity e = addCluster(it); ((EntityInternal) e).addLocations(Arrays.asList(it)); if (e instanceof Startable) { Task<?> task = Entities.submit(this, Effectors .invocation(e, START, ImmutableMap.of("locations", ImmutableList.of(it))).asTask()); tasks.put(e, task); } } waitForTasksOnStart(tasks); ServiceStateLogic.setExpectedState(this, Lifecycle.RUNNING); sensors().set(SERVICE_UP, true); } catch (Exception e) { ServiceStateLogic.setExpectedState(this, Lifecycle.ON_FIRE); throw Exceptions.propagate(e); } } protected void waitForTasksOnStart(Map<Entity, Task<?>> tasks) { // TODO Could do best-effort for waiting for remaining tasks, rather than failing on first? for (Map.Entry<Entity, Task<?>> entry : tasks.entrySet()) { try { entry.getValue().get(); } catch (InterruptedException e) { Thread.currentThread().interrupt(); throw Throwables.propagate(e); } catch (ExecutionException ee) { throw Throwables.propagate(ee.getCause()); } } } @Override public void stop() { ServiceStateLogic.setExpectedState(this, Lifecycle.STOPPING); try { Iterable<Entity> stoppableChildren = Iterables.filter(getChildren(), Predicates.instanceOf(Startable.class)); Task<?> invoke = Entities.invokeEffector(this, stoppableChildren, Startable.STOP); if (invoke != null) invoke.get(); ServiceStateLogic.setExpectedState(this, Lifecycle.STOPPED); sensors().set(SERVICE_UP, false); } catch (Exception e) { ServiceStateLogic.setExpectedState(this, Lifecycle.ON_FIRE); throw Exceptions.propagate(e); } } @Override public void restart() { throw new UnsupportedOperationException(); } @Override public Integer getFabricSize() { int result = 0; for (Entity child : getChildren()) { result += GroovyJavaMethods.<Integer>elvis(child.getAttribute(Changeable.GROUP_SIZE), 0); } return result; } @Override public boolean removeChild(Entity child) { boolean changed = super.removeChild(child); if (changed) { removeMember(child); } return changed; } protected Map getCustomChildFlags() { Map result = getConfig(CUSTOM_CHILD_FLAGS); return (result == null) ? ImmutableMap.of() : result; } protected Entity addCluster(Location location) { String locationName = elvis(location.getDisplayName(), location.getDisplayName(), null); Map creation = Maps.newLinkedHashMap(); creation.putAll(getCustomChildFlags()); if (truth(getDisplayNamePrefix()) || truth(getDisplayNameSuffix())) { String displayName = "" + elvis(getDisplayNamePrefix(), "") + elvis(locationName, "unnamed") + elvis(getDisplayNameSuffix(), ""); creation.put("displayName", displayName); } logger.info("Creating entity in fabric {} at {}{}", new Object[] { this, location, (creation != null && !creation.isEmpty() ? ", properties " + creation : "") }); Entity entity = createCluster(location, creation); if (locationName != null) { if (entity.getDisplayName() == null) ((EntityLocal) entity) .setDisplayName(entity.getEntityType().getSimpleName() + " (" + locationName + ")"); else if (!entity.getDisplayName().contains(locationName)) ((EntityLocal) entity).setDisplayName(entity.getDisplayName() + " (" + locationName + ")"); } if (entity.getParent() == null) entity.setParent(this); // Continue to call manage(), because some uses of NodeFactory (in tests) still instantiate the // entity via its constructor Entities.manage(entity); addMember(entity); return entity; } protected Entity createCluster(Location location, Map flags) { EntitySpec<?> memberSpec = getMemberSpec(); if (memberSpec != null) { return addChild(EntitySpec.create(memberSpec).configure(flags)); } EntityFactory<?> factory = getFactory(); if (factory == null) { throw new IllegalStateException( "No member spec nor entity factory supplied for dynamic fabric " + this); } EntityFactory<?> factoryToUse = (factory instanceof EntityFactoryForLocation) ? ((EntityFactoryForLocation) factory).newFactoryForLocation(location) : factory; Entity entity = factoryToUse.newEntity(flags, this); if (entity == null) throw new IllegalStateException("EntityFactory factory routine returned null entity, in " + this); return entity; } }