1 import java.util.*;
2
3 public class RemoveNullKeyValueUtils {
4 /*移除Map中值为空的键值对*/
5 public static void removeNullEntry(Map map) {
6 removeNullKey(map);
7 removeNullValue(map);
8 }
9 /*移除键为空的键值对*/
10 public static void removeNullKey(Map map) {
11 Set set = map.keySet();
12 for (Iterator iterator = set.iterator(); iterator.hasNext(); ) {
13 Object obj = (Object) iterator.next();
14 remove(obj, iterator);
15 }
16 }
17 /*移除值为空的键值对*/
18 public static void removeNullValue(Map map) {
19 Set set = map.keySet();
20 for (Iterator iterator = set.iterator(); iterator.hasNext(); ) {
21 Object obj = (Object) iterator.next();
22 Object value = (Object) map.get(obj);
23 remove(value, iterator);
24 }
25 }
26
27 private static void remove(Object obj, Iterator iterator) {
28 if (obj instanceof String) {
29 String str = (String) obj;
30 if (str == null || str.trim().isEmpty()) {
31 iterator.remove();
32 }
33 } else if (obj instanceof Collection) {
34 Collection col = (Collection) obj;
35 if (col == null || col.isEmpty()) {
36 iterator.remove();
37 }
38
39 } else if (obj instanceof Map) {
40 Map temp = (Map) obj;
41 if (temp == null || temp.isEmpty()) {
42 iterator.remove();
43 }
44
45 } else if (obj instanceof Object[]) {
46 Object[] array = (Object[]) obj;
47 if (array == null || array.length <= 0) {
48 iterator.remove();
49 }
50 } else {
51 if (obj == null) {
52 iterator.remove();
53 }
54 }
55 }
56 }
