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.core.enricher; import static com.google.common.base.Preconditions.checkState; import java.util.Map; import org.apache.brooklyn.api.entity.EntityLocal; import org.apache.brooklyn.api.mgmt.rebind.RebindSupport; import org.apache.brooklyn.api.mgmt.rebind.mementos.EnricherMemento; import org.apache.brooklyn.api.sensor.AttributeSensor; import org.apache.brooklyn.api.sensor.Enricher; import org.apache.brooklyn.api.sensor.EnricherType; import org.apache.brooklyn.api.sensor.Sensor; import org.apache.brooklyn.config.ConfigKey; import org.apache.brooklyn.core.config.ConfigKeys; import org.apache.brooklyn.core.entity.Entities; import org.apache.brooklyn.core.entity.EntityInternal; import org.apache.brooklyn.core.mgmt.rebind.BasicEnricherRebindSupport; import org.apache.brooklyn.core.objs.AbstractEntityAdjunct; import org.apache.brooklyn.util.core.flags.TypeCoercions; import com.google.common.base.Objects; import com.google.common.collect.Maps; /** * Base {@link Enricher} implementation; all enrichers should extend this or its children */ public abstract class AbstractEnricher extends AbstractEntityAdjunct implements Enricher { public static final ConfigKey<Boolean> SUPPRESS_DUPLICATES = ConfigKeys.newBooleanConfigKey( "enricher.suppressDuplicates", "Whether duplicate values published by this enricher should be suppressed"); private final EnricherDynamicType enricherType; protected Boolean suppressDuplicates; public AbstractEnricher() { this(Maps.newLinkedHashMap()); } public AbstractEnricher(Map<?, ?> flags) { super(flags); enricherType = new EnricherDynamicType(this); if (isLegacyConstruction() && !isLegacyNoConstructionInit()) { init(); } } @Override public RebindSupport<EnricherMemento> getRebindSupport() { return new BasicEnricherRebindSupport(this); } @SuppressWarnings("unchecked") @Override public RelationSupportInternal<Enricher> relations() { return (RelationSupportInternal<Enricher>) super.relations(); } @Override public EnricherType getEnricherType() { return enricherType.getSnapshot(); } @Override public void setEntity(EntityLocal entity) { super.setEntity(entity); Boolean suppressDuplicates = getConfig(SUPPRESS_DUPLICATES); if (suppressDuplicates != null) this.suppressDuplicates = suppressDuplicates; } @Override protected void onChanged() { requestPersist(); } @Override protected <T> void emit(Sensor<T> sensor, Object val) { checkState(entity != null, "entity must first be set"); if (val == Entities.UNCHANGED) { return; } if (val == Entities.REMOVE) { ((EntityInternal) entity).removeAttribute((AttributeSensor<T>) sensor); return; } T newVal = TypeCoercions.coerce(val, sensor.getTypeToken()); if (sensor instanceof AttributeSensor) { if (Boolean.TRUE.equals(suppressDuplicates)) { T oldValue = entity.getAttribute((AttributeSensor<T>) sensor); if (Objects.equal(oldValue, newVal)) return; } entity.sensors().set((AttributeSensor<T>) sensor, newVal); } else { entity.sensors().emit(sensor, newVal); } } }