/*
* Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
*
* Licensed 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 com.hazelcast.util;
import java.util.HashMap;
import java.util.Map;
/**
* Utility class for Maps
*/
public final class MapUtil {
private static final double HASHMAP_DEFAULT_LOAD_FACTOR = 0.75;
private MapUtil() { }
/**
* Utility method that creates an {@link java.util.HashMap} with its initialCapacity calculated
* to minimize rehash operations
*/
public static <K, V> Map<K, V> createHashMap(int expectedMapSize) {
int initialCapacity = (int) (expectedMapSize / HASHMAP_DEFAULT_LOAD_FACTOR) + 1;
return new HashMap<K, V>(initialCapacity);
}
/**
* Test the given map and return {@code true} if the map is null or empty.
* @param map the map to test
* @return {@code true} if {@code map} is null or empty, otherwise {@code false}.
*/
public static boolean isNullOrEmpty(Map map) {
return map == null || map.isEmpty();
}
}