1 package Test;

 2

 3 import java.util.HashMap;

 4 import java.util.Map;

 5

 6 public class MapTest {

 7     public static void main(String[]args){

 8         Map map1=new HashMap();

 9         Map map2=new HashMap();

10         map1.put("1","aaa1");

11         map1.put("1","bbb2");

12         map2.put("10","aaaa10");

13         map2.put("11","bbbb11");

14

15         System.out.println("map1.get(\"1\")="+map1.get("1"));

16         System.out.println("map1.remove(\"1\")="+map1.remove("1"));

17         map1.putAll(map2);

18         map2.clear();

19         System.out.println("map1 IsEmpty?="+map1.isEmpty());

20         System.out.println("map2 IsEmpty?="+map2.isEmpty());

21         System.out.println("map中的键值对数size"+map1.size());

22         System.out.println("KeySet="+map1.keySet());

23         System.out.println("value="+map1.values());

24         System.out.println("entrySet="+map1.entrySet());

25         System.out.println("map1是否包含键:11="+map1.containsKey("11"));

26         System.out.println("map1是否包含值:aaa1="+map1.containsValue("aaa1"));

27     }

28

29 }

 1 package Test;

 2

 3 import java.util.HashMap;

 4 import java.util.LinkedHashMap;

 5 import java.util.Map;

 6 import java.util.TreeMap;

 7

 8 public class MapSortExample {

 9     public static void main(String[]args){

10         Map map1=new HashMap();

11         Map map2=new LinkedHashMap();

12         for(int i=0;i<10;i++){

13             double s=Math.random()*100;

14             map1.put(new Integer((int) s),"第 "+i+"个放入的元素:"+s+"\n");

15             map2.put(new Integer((int) s),"第 "+i+"个放入的元素:"+s+"\n");

16         }

17

18

19         System.out.println("未排序前HashMap:"+map1);

20         System.out.println("未排序前LinkedHashMap:"+map2);

21         Map sortedMap=new TreeMap(map1);

22         System.out.println("排序后:"+sortedMap);

23         System.out.println("排序前:"+new TreeMap(map2));

24     }

25

26 }