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 }
