| /* |
| * 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.onlab.util; |
| |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| |
| import org.apache.commons.lang3.concurrent.ConcurrentInitializer; |
| |
| /** |
| * Creates an instance of new ConcurrentHashMap on each {@link #get()} call. |
| * <p> |
| * To be used with |
| * {@link org.apache.commons.lang3.concurrent.ConcurrentUtils#createIfAbsent() |
| * ConcurrentUtils#createIfAbsent} |
| * |
| * @param <K> ConcurrentHashMap key type |
| * @param <V> ConcurrentHashMap value type |
| */ |
| public final class NewConcurrentHashMap<K, V> |
| implements ConcurrentInitializer<ConcurrentMap<K, V>> { |
| |
| public static final NewConcurrentHashMap<?, ?> INSTANCE = new NewConcurrentHashMap<>(); |
| |
| @SuppressWarnings("unchecked") |
| public static <K, V> NewConcurrentHashMap<K, V> ifNeeded() { |
| return (NewConcurrentHashMap<K, V>) INSTANCE; |
| } |
| |
| @Override |
| public ConcurrentMap<K, V> get() { |
| return new ConcurrentHashMap<>(); |
| } |
| } |