Map按value排序

最新推荐文章于 2021-02-24 05:22:18 发布

原创最新推荐文章于 2021-02-24 05:22:18 发布 · 903 阅读

0 ·

CC 4.0 BY-SA版权

java 专栏收录该内容

9 篇文章

订阅专栏

public class CollectionUtil {
    /**
     * map按照value排序
     * @param <T> map中value类型
     * @param map map对象
     * @param comparator
     * @return
     */
    public static <T> Map<String,T> sortMapByValue(Map<String, T> map,Comparator<Map.Entry<String,T>> comparator) {   
        List<Entry<String, T>>  list = new LinkedList<Entry<String, T>>(map.entrySet());   
        Collections.sort(list,(Comparator<Map.Entry<String,T>>) comparator);   
        Map<String,T> result = new LinkedHashMap<String,T>();   
        for (Iterator<Entry<String, T>> it = list.iterator(); it.hasNext();) {
          Entry<String, T> entry = it.next();   
          result.put(entry.getKey(), entry.getValue());   
        }   
        return result;
    }
    /**
     * 测试函数
     * @param args
     */
    public static void main(String[] args) {
        Map<String, Float> map = new LinkedHashMap<String, Float>();   
        map.put("7og",10f);   
        map.put("apple",40f);   
        map.put("2oy",30f);   
        map.put("4at",20f);   
        System.out.println(map);
        Map<String,Float> sortMap =  sortMapByValue(map, new Comparator<Map.Entry<String, Float>>() {
          @Override
          public int compare(Entry<String, Float> o1,Entry<String, Float> o2) {
            //控制升序或降序及比较的具体内容
            return o1.getValue().compareTo(o2.getValue());  
          }
        });
        System.out.println(sortMap);
    }
}