MapUtil.java

package com.boco.nbd.wios.log.util;

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

/**
 * @Description: TODO
 * @Author: ZQY
 * @Date: 2022/10/25
 **/
public class MapUtil {

    private static Comparator<Map.Entry> comparatorByKeyAsc = (Map.Entry o1, Map.Entry o2) -> {
        if (o1.getKey() instanceof Comparable) {
            return ((Comparable) o1.getKey()).compareTo(o2.getKey());
        }
        throw new UnsupportedOperationException("键的类型尚未实现Comparable接口");
    };


    private static Comparator<Map.Entry> comparatorByKeyDesc = (Map.Entry o1, Map.Entry o2) -> {
        if (o1.getKey() instanceof Comparable) {
            return ((Comparable) o2.getKey()).compareTo(o1.getKey());
        }
        throw new UnsupportedOperationException("键的类型尚未实现Comparable接口");
    };


    private static Comparator<Map.Entry> comparatorByValueAsc = (Map.Entry o1, Map.Entry o2) -> {
        if (o1.getValue() instanceof Comparable) {
            return ((Comparable) o1.getValue()).compareTo(o2.getValue());
        }
        throw new UnsupportedOperationException("值的类型尚未实现Comparable接口");
    };


    private static Comparator<Map.Entry> comparatorByValueDesc = (Map.Entry o1, Map.Entry o2) -> {
        if (o1.getValue() instanceof Comparable) {
            return ((Comparable) o2.getValue()).compareTo(o1.getValue());
        }
        throw new UnsupportedOperationException("值的类型尚未实现Comparable接口");
    };

    /**
     * 按键升序排列
     */
    public static <K, V> Map<K, V> sortByKeyAsc(Map<K, V> originMap) {
        if (originMap == null) {
            return null;
        }
        return sort(originMap, comparatorByKeyAsc);
    }

    /**
     * 按键降序排列
     */
    public static <K, V> Map<K, V> sortByKeyDesc(Map<K, V> originMap) {
        if (originMap == null) {
            return null;
        }
        return sort(originMap, comparatorByKeyDesc);
    }


    /**
     * 按值升序排列
     */
    public static <K, V> Map<K, V> sortByValueAsc(Map<K, V> originMap) {
        if (originMap == null) {
            return null;
        }
        return sort(originMap, comparatorByValueAsc);
    }

    /**
     * 按值降序排列
     */
    public static <K, V> Map<K, V> sortByValueDesc(Map<K, V> originMap) {
        if (originMap == null) {
            return null;
        }
        return sort(originMap, comparatorByValueDesc);
    }

    private static <K, V> Map<K, V> sort(Map<K, V> originMap, Comparator<Map.Entry> comparator) {
        return originMap.entrySet()
                .stream()
                .sorted(comparator)
                .collect(
                        Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue, (e1, e2) -> e2,
                                LinkedHashMap::new));
    }

    /**
     * 转换Map
     *
     * @param map
     * @return
     */
    public static Map<String, Integer> getMap(List<Map<String, Object>> map) {

        String field = "key";
        Map<String, Integer> genderCount = new HashMap<>(8);
        for (Map<String, Object> kv : map) {
            String key = null;
            Integer value = null;
            for (Map.Entry<String, Object> entry : kv.entrySet()) {

                if (field.equals(entry.getKey())) {

                    key = (String) entry.getValue();
                } else {
                    value = Integer.parseInt(entry.getValue().toString());
                }
            }
            genderCount.put(key, value);
        }
        return genderCount;
    }

}