Map根据key值排序

import java.util.*;

/**
 * @author soul
 * @version version
 * @date 2019/12/13 17:12
 */
public class MapSortUtil {

    /**
     * 对 map根据 key值排序
     *
     * @param map
     */
    public static void mapSortByKey(Map map) {

        //传进来一个key的比较器对象来构造treemap
        Map<String, String> stu = new TreeMap<>(new MyComparator());
        stu.putAll(map);
        Set<String> keySet = stu.keySet();
        Iterator it = keySet.iterator();
        while (it.hasNext()) {
            String next = (String) it.next();
            System.out.println(next);
        }
    }

    public static void main(String[] args) {
        Map<String, String> stu = new HashMap<>();
        stu.put("account", "account");
        stu.put("bat", "bat");
        stu.put("IBM","bat")
        mapSortByKey(stu);
 
    }

}

/**
 * 内部类
 */
class MyComparator implements Comparator<String> {
    @Override
    public int compare(String o1, String o2) {
        return o1.compareTo(o2);
    }
}

https://blog.csdn.net/top_code/article/details/8528954

java8写法：

List<Map.Entry<Integer,Integer>>list = map.entrySet().stream()
      .sorted((entry1, entry2) -> entry1.getValue().compareTo(entry2.getValue()))
      .collect(Collectors.toList());