| /* |
| * 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.chef.util; |
| |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import org.jclouds.javax.annotation.Nullable; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableMap; |
| import com.google.common.collect.ImmutableSet; |
| |
| /** |
| * Utility methods to work with collections. |
| */ |
| public class CollectionUtils { |
| |
| /** |
| * Creates an immutable list with the elements of the given list. If the |
| * input list is <code>null</code>, it returns an empty list. |
| * |
| * @param input |
| * The list used to build the immutable one. |
| * @return An immutable list with the elements of the given list. |
| */ |
| public static <T> ImmutableList<T> copyOfOrEmpty(@Nullable List<T> input) { |
| return input == null ? ImmutableList.<T> of() : ImmutableList.copyOf(input); |
| } |
| |
| /** |
| * Creates an immutable set with the elements of the given set. If the input |
| * set is <code>null</code>, it returns an empty set. |
| * |
| * @param input |
| * The set used to build the immutable one. |
| * @return An immutable set with the elements of the given set. |
| */ |
| public static <T> ImmutableSet<T> copyOfOrEmpty(@Nullable Set<T> input) { |
| return input == null ? ImmutableSet.<T> of() : ImmutableSet.copyOf(input); |
| } |
| |
| /** |
| * Creates an immutable map with the elements of the given map. If the input |
| * map is <code>null</code>, it returns an empty map. |
| * |
| * @param input |
| * The map used to build the immutable one. |
| * @return An immutable map with the elements of the given map. |
| */ |
| public static <K, V> ImmutableMap<K, V> copyOfOrEmpty(@Nullable Map<K, V> input) { |
| return input == null ? ImmutableMap.<K, V> of() : ImmutableMap.copyOf(input); |
| } |
| } |