利用Java8 stream对Map排序

Posted 2021-03-20

原文地址：

https://blog.csdn.net/u013719012/article/details/82117477

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

public class Main2 {
    public static void main(String[] args) {
        Map<Integer, String> abcMap = new HashMap<>();
        abcMap.put(19, "19");
        abcMap.put(14, "14");
        abcMap.put(2, "2");
        LinkedHashMap<Integer, String> linkedMap = new LinkedHashMap<>();
        // 将HashMap转换成LinkedHashMap
        abcMap.entrySet().stream().sorted(Map.Entry.comparingByKey())
                .forEachOrdered(entry -> linkedMap.put(entry.getKey(), entry.getValue()));
        // 如果想要转换成List
        List collect = linkedMap.entrySet().stream().map(Map.Entry::getValue).collect(Collectors.toList());
        List collect2 = linkedMap.values().stream().collect(Collectors.toList());
        List collect3 = new ArrayList<>(linkedMap.values());

        for (Object o : collect3) {
            System.out.println(o);
        }
    }

}