com.iohao.game.common.kit.CollKit Maven / Gradle / Ivy

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/*
 * ioGame
 * Copyright (C) 2021 - present  渔民小镇 （[email protected]、[email protected]） . All Rights Reserved.
 * # iohao.com . 渔民小镇
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see .
 */
package com.iohao.game.common.kit;


import lombok.experimental.UtilityClass;

import java.util.*;
import java.util.function.Function;
import java.util.stream.Collectors;

/**
 * 集合相关工具
 *
 * @author 渔民小镇
 * @date 2022-01-14
 */
@UtilityClass
public class CollKit {
    /**
     * 分组统计
     *      *     key is 元素下标
     *     value is 元素下标对应的数量
     * 
     *
     *      *     示例
     *     handCards: [11, 11, 11, 21, 46, 33,33, 18, 18, 18, 18]
     *
     *     得到的 map {
     *         11 : 3
     *         18 : 4
     *         21 : 1
     *         33 : 2
     *         46 : 1
     *     }
     * 
     *
     * @param list 元素列表
     * @return map
     */
    public Map groupCounting(List list) {
        return list.stream().
                collect(
                        Collectors.groupingBy(Function.identity(), Collectors.summingInt(e -> 1))
                );
    }

    public boolean notEmpty(Collection collection) {
        return !isEmpty(collection);
    }

    public boolean isEmpty(Collection collection) {
        return collection == null || collection.isEmpty();
    }

    public  Optional findAny(Set set) {
        if (isEmpty(set)) {
            return Optional.empty();
        }

        return set.stream().findAny();
    }
}