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.aws.ec2.compute.suppliers; import static com.google.common.collect.Iterables.filter; import static com.google.common.collect.Iterables.transform; import static org.jclouds.aws.ec2.options.AWSDescribeImagesOptions.Builder.filters; import java.util.Map.Entry; import java.util.concurrent.Callable; import javax.annotation.Resource; import javax.inject.Inject; import javax.inject.Named; import javax.inject.Singleton; import org.jclouds.compute.domain.Image; import org.jclouds.compute.reference.ComputeServiceConstants; import org.jclouds.ec2.compute.functions.EC2ImageParser; import org.jclouds.ec2.compute.strategy.DescribeImagesParallel; import org.jclouds.ec2.options.DescribeImagesOptions; import org.jclouds.logging.Logger; import com.google.common.base.Predicates; import com.google.common.collect.ImmutableMap; import com.google.common.collect.Iterables; import com.google.common.collect.Multimap; import com.google.common.collect.ImmutableMap.Builder; import com.google.inject.assistedinject.Assisted; /** * * @author Adrian Cole */ @Singleton public class CallForImages implements Callable<Iterable<Image>> { public interface Factory { CallForImages parseImagesFromRegionsUsingFilter(Iterable<String> regions, Multimap<String, String> filter); } @Resource @Named(ComputeServiceConstants.COMPUTE_LOGGER) protected Logger logger = Logger.NULL; private final Iterable<String> regions; private final DescribeImagesParallel describer; private final EC2ImageParser parser; private final Multimap<String, String> filter; @Inject protected CallForImages(DescribeImagesParallel describer, EC2ImageParser parser, @Assisted Iterable<String> regions, @Assisted Multimap<String, String> filter) { this.regions = regions; this.describer = describer; this.filter = filter; this.parser = parser; } public Iterable<Image> call() { logger.debug(">> providing images"); Builder<String, DescribeImagesOptions> builder = ImmutableMap.builder(); for (String region : regions) builder.put(region, filters(filter)); Iterable<Entry<String, DescribeImagesOptions>> queries = builder.build().entrySet(); Iterable<Image> returnVal = filter(transform(describer.apply(queries), parser), Predicates.notNull()); if (logger.isDebugEnabled()) logger.debug("<< images(%s)", Iterables.size(returnVal)); return returnVal; } @Override public String toString() { return String.format("describingImages(filter=%s,regions=%s)", filter, regions); } }