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.virtualbox.functions; import static com.google.common.base.Preconditions.checkNotNull; import java.util.Map; import java.util.concurrent.ExecutionException; import javax.annotation.Resource; import javax.inject.Inject; import javax.inject.Named; import javax.inject.Singleton; import org.jclouds.compute.reference.ComputeServiceConstants; import org.jclouds.logging.Logger; import org.jclouds.virtualbox.util.MachineNameOrIdAndNicSlot; import org.virtualbox_4_2.VirtualBoxManager; import com.google.common.base.Strings; import com.google.common.base.Supplier; import com.google.common.cache.AbstractLoadingCache; import com.google.common.collect.Maps; /** * A {@link LoadingCache} for ip addresses. If the requested ip address has been * previously extracted this returns it, if not it calls vbox api. * * @author Andrea Turli * */ @Singleton public class IpAddressesLoadingCache extends AbstractLoadingCache<MachineNameOrIdAndNicSlot, String> { @Resource @Named(ComputeServiceConstants.COMPUTE_LOGGER) protected Logger logger = Logger.NULL; private final Map<MachineNameOrIdAndNicSlot, String> masters = Maps.newHashMap(); private final Supplier<VirtualBoxManager> manager; @Inject public IpAddressesLoadingCache(Supplier<VirtualBoxManager> manager) { this.manager = checkNotNull(manager, "vboxmanager"); } @Override public synchronized String get(MachineNameOrIdAndNicSlot machineNameOrIdAndNicPort) throws ExecutionException { if (masters.containsKey(machineNameOrIdAndNicPort)) { return masters.get(machineNameOrIdAndNicPort); } String query = String.format("/VirtualBox/GuestInfo/Net/%s/V4/IP", machineNameOrIdAndNicPort.getSlotText()); String ipAddress = Strings.nullToEmpty(manager.get().getVBox() .findMachine(machineNameOrIdAndNicPort.getMachineNameOrId()).getGuestPropertyValue(query)); if (!ipAddress.isEmpty()) { logger.debug("<< vm(%s) has IP address(%s) at slot(%s)", machineNameOrIdAndNicPort.getMachineNameOrId(), ipAddress, machineNameOrIdAndNicPort.getSlotText()); } masters.put(machineNameOrIdAndNicPort, ipAddress); return ipAddress; } @Override public String getIfPresent(Object key) { return masters.get((MachineNameOrIdAndNicSlot) key); } @Override public void invalidate(Object key) { masters.remove(key); } }