Map按照Key排序和Map按照Value排序

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Map数组按照Value排序（升序）
   import java.util.ArrayList;
   import java.util.Collections;
   import java.util.Comparator;
   import java.util.Iterator;
   import java.util.LinkedHashMap;
   import java.util.Map;
   import java.util.Map.Entry;

   public class LinkedHashMapSortWithValue {
       public static void main(String[] args) throws Exception {
           // TODO code application logic here
           Map<String, Integer> myMap = new LinkedHashMap();
           myMap.put("1", 1);
           myMap.put("2", 4);
           myMap.put("3", 3);
           myMap.put("4", 9);
           myMap.put("5", 6);
           myMap.put("6", 2);

           printMap(myMap);

           myMap = sortMap(myMap);

           printMap(myMap);
       }

       private static void printMap(Map map){
           System.out.println("===================mapStart==================");
           Iterator it = map.entrySet().iterator();
           while(it.hasNext()){
               Map.Entry entry = (Map.Entry) it.next();
               System.out.println(entry.getKey() + ":" + entry.getValue());
           }
           System.out.println("===================mapEnd==================");
       }

       public static Map sortMap(Map oldMap) {
           ArrayList<Map.Entry<String, Integer>> list = new ArrayList<Map.Entry<String, Integer>>(oldMap.entrySet());
           Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {

               @Override
               public int compare(Entry<java.lang.String, Integer> arg0,
                       Entry<java.lang.String, Integer> arg1) {
                   return arg0.getValue() - arg1.getValue();
               }
           });
           Map newMap = new LinkedHashMap();
           for (int i = 0; i < list.size(); i++) {
               newMap.put(list.get(i).getKey(), list.get(i).getValue());
           }
           return newMap;
       }
   }


Map数组按照Key降序和升序排列
   import java.util.Comparator;
   import java.util.TreeMap;
   public class TreeMapSortWithKey {
    public static void main(String[] args) {
     TreeMap<Integer,Integer> map1 = new TreeMap<Integer,Integer>(); //默认的TreeMap升序排列
     TreeMap<Integer,Integer> map2= new TreeMap<Integer,Integer>(new Comparator<Integer>(){
       /*
             * int compare(Object o1, Object o2) 返回一个基本类型的整型，
             * 返回负数表示：o1 小于o2，
             * 返回0 表示：o1和o2相等，
             * 返回正数表示：o1大于o2。
             */
      public int compare(Integer a,Integer b){
       return b-a;
      }
      });
     map2.put(1,2);
     map2.put(2,4);
     map2.put(7, 1);
     map2.put(5,2);
     System.out.println("Map2="+map2);

     map1.put(1,2);
     map1.put(2,4);
     map1.put(7, 1);
     map1.put(5,2);
     System.out.println("map1="+map1);
    }
   }

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