List查询重复值的个数，并根据重复的数目从多到少排列

 package ttt;

 import java.nio.MappedByteBuffer;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 import java.util.TreeMap;
 import java.util.TreeSet;

 public class list查重 {

     public static void main(String[] args) {

         List <String> wordList = new ArrayList<>();
         wordList.add("age");
         wordList.add("age");
         wordList.add("age");
         wordList.add("egg");
         wordList.add("dog");
         wordList.add("copy");
         wordList.add("copy");
         wordList.add("dog");
         wordList.add("dog");
         wordList.add("copy");
         wordList.add("battle");
         wordList.add("battle");
         wordList.add("battle");
         wordList.add("battle");
         wordList.add("battle");
         wordList.add("battle");
         wordList.add("age");

         rangeWords(wordList);
     }

     private static void rangeWords(List<String> wordList) {
         Set<String> uniqueSet = new HashSet<>(wordList);
         Map<String,Integer> maap= new HashMap<>();
         for (String temp : uniqueSet) {
             int num = Collections.frequency(wordList, temp);
             maap.put(temp, num);
         }
         List<Entry<String,Integer>> list = new ArrayList<>(maap.entrySet());
         Collections.sort(list, new Comparator<Map.Entry<String,Integer>>() {
             @Override
             public int compare(Map.Entry<String,Integer> cmap,Map.Entry<String,Integer> cmap2){
                 return cmap2.getValue()-cmap.getValue();
             }
         });

         printMap(list);
     }

     private static void printMap(List<Entry<String, Integer>> list) {
         for (Map.Entry entry : list) {
             System.out.println(entry.getKey()+"  "+entry.getValue());
         }
     }

 }