1. //循環遍歷map的方法
2. public class MapF {
3. public static void main(String[] args) {
4. Map<String, Integer> tempMap = new HashMap<String, Integer>();
5. tempMap.put("a","12");
6. tempMap.put("b","34");
7. tempMap.put("c","56");
8. // JDK1.4中
9. // 遍歷方法一 hashmap entrySet() 遍歷
10. Iterator it = tempMap.entrySet().iterator();
11. while (it.hasNext()) {
12. Map.Entry entry = (Map.Entry) it.next();
13. Object key = entry.getKey();
14. Object value = entry.getValue();
15. System.out.println("key=" + key + " value=" + value);
16. }
17. System.out.println("");
18. // JDK1.5中,應用新特性For-Each循環
19. // 遍歷方法二
20. for (Map.Entry<String, Integer> entry : tempMap.entrySet()) {
21. String key = entry.getKey().toString();
22. String value = entry.getValue().toString();
23. System.out.println("key=" + key + " value=" + value);
24. }
25. System.out.println("");
26. // 遍歷方法三 hashmap keySet() 遍歷
27. for (Iterator i = tempMap.keySet().iterator(); i.hasNext();) {
28. Object obj = i.next();
29. System.out.println(obj);// 循環輸出key
30. System.out.println("key=" + obj + " value=" + tempMap.get(obj));
31. }
32. for (Iterator i = tempMap.values().iterator(); i.hasNext();) {
33. Object obj = i.next();
34. System.out.println(obj);// 循環輸出value
35. }
36. // 遍歷方法四 treemap keySet()遍歷
37. for (Object o : tempMap.keySet()) {
38. System.out.println("key=" + o + " value=" + tempMap.get(o));
39. }
40. System.out.println("11111");
41. // java如何遍歷Map <String, ArrayList> map = new HashMap <String,
42. // ArrayList>();
43. System.out.println("java 遍歷Map <String, ArrayList> map = new HashMap<String, ArrayList>();");
44. Map<String, ArrayList> map = new HashMap<String, ArrayList>();
45. Set<String> keys = map.keySet();
46. Iterator<String> iterator = keys.iterator();
47. while (iterator.hasNext()) {
48. String key = iterator.next();
49. ArrayList arrayList = map.get(key);
50. for (Object o : arrayList) {
51. System.out.println(o);
52. }
53. }
54. Map<String, List> map = new HashMap<String, List>();
55. for (Map.Entry entry : map.entrySet()) {
56. String key = entry.getKey().toString();
57. List<String> list= (List) entry.getValue();
58. for (String value : list) {
59. System.out.println(key + "====" + value);
60. }
61. }
62. }
63. }

5種遍歷集合