TreeMap按value值进行排序

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public class GiveMeMore {private static final int counter = 1;public static void main(String[] args) {try {BufferedReader in = new BufferedReader(new InputStreamReader(System.in));System.out.print("请输入:");String text = in.readLine();char[] a = text.toCharArray();Map m = new TreeMap();for (int i = 0; i < a.length; i++) {if (!m.containsKey(a[i])) {m.put(a[i], counter);} else { //int num = m.get(a[i]);int num =Integer.parseInt(m.get(a[i]).toString()) ; m.put(a[i], num + 1);}}System.out.println(m); List arrayList = new ArrayList(m.entrySet());  Collections.sort(arrayList, new Comparator(){   public int compare(Object o1, Object o2) {    Map.Entry obj1 = (Map.Entry) o1;    Map.Entry obj2 = (Map.Entry) o2;    return ((Integer) obj2.getValue()).compareTo((Integer)obj1.getValue());    }  });   System.out.println(arrayList);} catch (Exception e) {e.printStackTrace();}}}

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