依据guigui111111的建议：先把Map按Key从大到小排序，然后再把Key和Value互换。这也是一种非常好的思路，我写了一下代码，顺便贴上来，供大家參考与分享。

package shuai.study.map;import java.util.Comparator;import java.util.HashMap;import java.util.Iterator;import java.util.Map;import java.util.Map.Entry;import java.util.TreeMap;/** * @author shengshu *  */public class UniqueMap1 {	// Transfer to sorted Map	public static Map
     
       transferToSortedMap(Map
      
        map) {		// Define comparator for TreeMap		// Note: Sort according to descending, because retain the smaller Key's record when exchanging Map's Key and Value		Map
       
         sort_map = new TreeMap
        
         (new Comparator
         
          () {			@Override			public int compare(String key1, String key2) {				return key2.hashCode() - key1.hashCode();			}		});		sort_map.putAll(map);		return sort_map;	}	// Exchange Map's Key and Value	public static Map
          
            exchangeMap(Map
           
             map) { Map
            
              exchange_map = new TreeMap
             
              (); for (String key : map.keySet()) { String value = map.get(key); exchange_map.put(value, key); } return exchange_map; } // Print Map public static void printMap(Map
              
                map) { Iterator
               
                
                 > iterator = map.entrySet().iterator(); while (iterator.hasNext()) { Entry
                 
                   entry = iterator.next(); String key = entry.getKey(); String value = entry.getValue(); System.out.println(key + " --> " + value); } } public static void main(String[] args) { Map
                  
                    map = new HashMap
                   
                    (); map.put("A", "1"); map.put("C", "3"); map.put("D", "2"); map.put("B", "3"); map.put("E", "3"); // Sort Map by descending order // Note: Sort according to descending, because retain the smaller Key's record when exchanging Map's Key and Value Map
                    
                      sort_map = UniqueMap1.transferToSortedMap(map); // Exchange Key and Value for overlapping repetition record Map
                     
                       exchange_map = UniqueMap1.exchangeMap(sort_map); // Exchange Map for recovering Key and Value, this Map is what we want exchange_map = UniqueMap1.exchangeMap(exchange_map); // Print Map UniqueMap1.printMap(exchange_map); }}