1. import java.util.Collection;
   
2. import java.util.HashMap;
   
3. import java.util.Iterator;
   
4. import java.util.Map;
   
5. import java.util.Set;
   
6. 
   
7. 
   
8. public class Test{
   
9. 
   
10. public static void main(String[] args) {
    
11. 
    
12. Map<String,Integer> map = new HashMap<String,Integer>();
    
13. 
    
14. map.put("1", 1);
    
15. map.put("2", 2);
    
16. map.put("3", 3);
    
17. map.put("4", 4);
    
18. 
    
19. work(map);
    
20. 
    
21. workByKeySet(map);
    
22. 
    
23. workByEntry(map);
    
24. 
    
25. }
    
26. 
    
27. 
    
28. //最常规的一种遍历方法
    
29. 
    
30. public static void work(Map<String, Integer> map) {
    
31. Collection<Integer> c = map.values();
    
32. Iterator it = c.iterator();
    
33. for (; it.hasNext();) {
    
34. System.out.print(it.next());
    
35. }
    
36. System.out.println();
    
37. }
    
38. 
    
39. //利用keyset进行遍历
    
40. 
    
41. public static void workByKeySet(Map<String, Integer> map) {
    
42. Set<String> key = map.keySet();
    
43. for (Iterator it = key.iterator(); it.hasNext();) {
    
44. String s = (String) it.next();
    
45. System.out.print(map.get(s));
    
46. }
    
47. System.out.println();
    
48. }
    
49. 
    
50. //第三种
    
51. 
    
52. public static void workByEntry(Map<String, Integer> map) {
    
53. Set<Map.Entry<String, Integer>> set = map.entrySet();
    
54. for (Iterator<Map.Entry<String, Integer>> it = set.iterator(); it.hasNext();) {
    
55. Map.Entry<String, Integer> entry = (Map.Entry<String, Integer>) it.next();
    
56. System.out.print("!!!!!" + entry.getKey() + "-------" + entry.getValue());
    
57. }
    
58. System.out.println();
    
59. }
    
60. }

复制代码

结果：
3214
3214
!!!!!3-------3!!!!!2-------2!!!!!1-------1!!!!!4-------4

我再添加一种遍历方法：JDK1.5中,应用新特性For-Each循环

//第四种 通过Map.values()遍历所有的value，但不能遍历key
  for (String v : map.values()) {
   System.out.println("value= " + v);
  }