core/src/main/java/org/jclouds/ohai/functions/MapSetToMultimap.java

/**
 * Licensed to jclouds, Inc. (jclouds) under one or more
 * contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  jclouds 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.ohai.functions;

import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;

import javax.inject.Singleton;

import com.google.common.base.Function;
import com.google.common.collect.LinkedHashMultimap;
import com.google.common.collect.Multimap;

/**
 * 
 * @author Adrian Cole
 */
@Singleton
public class MapSetToMultimap<K, V> implements Function<Map<K, Set<V>>, Multimap<K, V>> {

   @Override
   public Multimap<K, V> apply(Map<K, Set<V>> from) {
      Multimap<K, V> returnV = LinkedHashMultimap.create();
      for (Entry<K, Set<V>> entry : from.entrySet()) {
         for (V value : entry.getValue())
            returnV.put(entry.getKey(), value);
      }
      return returnV;
   }

}