Java8排序

List<Map.Entry<String,Integer>> list=new ArrayList<>();
list.addAll(map.entrySet());  
Collections.sort(list,new Comparator<Map.Entry<String, Integer>>() {
 
   @Override
   public int compare(Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2) {
        return o2.getValue()-o1.getValue();
   }
 
});



Map<String, Integer> valueResult = new HashMap<>();
Map<String, Integer> map = new HashMap<>();
map.entrySet().stream()
    .sorted(Map.Entry
        .comparingByValue())
        .forEachOrdered(b->valueResult.put(b.getKey(), b.getValue()));



 Set<Map.Entry<Integer, Integer>> entries = map.entrySet();
        // 根据map的value值正序排，相当于一个小顶堆
        PriorityQueue<Map.Entry<Integer, Integer>> queue = new PriorityQueue<>((o1, o2) -> o1.getValue() - o2.getValue());
        for (Map.Entry<Integer, Integer> entry : entries) {
            queue.offer(entry);
            if (queue.size() > k) {
                queue.poll();
            }
        }