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.jclouds.openstack.nova.v2_0.compute.functions; import static com.google.common.base.Preconditions.checkNotNull; import static com.google.common.collect.Iterables.filter; import static com.google.common.collect.Iterables.transform; import static com.google.common.collect.Sets.filter; import java.util.Set; import javax.inject.Inject; import org.jclouds.compute.ComputeService; import org.jclouds.compute.domain.NodeMetadata; import org.jclouds.compute.predicates.NodePredicates; import org.jclouds.domain.LocationScope; import org.jclouds.openstack.nova.v2_0.compute.predicates.AllNodesInGroupTerminated; import org.jclouds.openstack.nova.v2_0.domain.regionscoped.RegionAndName; import com.google.common.annotations.VisibleForTesting; import com.google.common.base.Function; import com.google.common.base.Predicate; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Multimap; import com.google.common.collect.Multimaps; public class OrphanedGroupsByRegionId implements Function<Set<? extends NodeMetadata>, Multimap<String, String>> { private final Predicate<RegionAndName> allNodesInGroupTerminated; @Inject protected OrphanedGroupsByRegionId(ComputeService computeService) { this(new AllNodesInGroupTerminated(checkNotNull(computeService, "computeService"))); } @VisibleForTesting OrphanedGroupsByRegionId(Predicate<RegionAndName> allNodesInGroupTerminated) { this.allNodesInGroupTerminated = checkNotNull(allNodesInGroupTerminated, "allNodesInGroupTerminated"); } public Multimap<String, String> apply(Set<? extends NodeMetadata> deadNodes) { Iterable<? extends NodeMetadata> nodesWithGroup = filter(deadNodes, NodePredicates.hasGroup()); Set<RegionAndName> regionAndGroupNames = ImmutableSet .copyOf(filter(transform(nodesWithGroup, new Function<NodeMetadata, RegionAndName>() { @Override public RegionAndName apply(NodeMetadata input) { String regionId = input.getLocation().getScope() == LocationScope.HOST ? input.getLocation().getParent().getId() : input.getLocation().getId(); return RegionAndName.fromRegionAndName(regionId, input.getGroup()); } }), allNodesInGroupTerminated)); Multimap<String, String> regionToRegionAndGroupNames = Multimaps.transformValues( Multimaps.index(regionAndGroupNames, RegionAndName.REGION_FUNCTION), RegionAndName.NAME_FUNCTION); return regionToRegionAndGroupNames; } }