移除键为空的键值对

有一个map里边的key是空，那么要移除掉这个空key的数据：

/*移除键为空的键值对*/
public static void removeNullKey(Map map) {
    Set set = map.keySet();
    for (Iterator iterator = set.iterator(); iterator.hasNext(); ) {
        Object obj = (Object) iterator.next();
        remove(obj, iterator);
    }
}

private static void remove(Object obj, Iterator iterator) {
    if (obj instanceof String) {
        String str = (String) obj;
        if (str == null || str.trim().isEmpty()) {
            iterator.remove();
        }
    } else if (obj instanceof Collection) {
        Collection col = (Collection) obj;
        if (col == null || col.isEmpty()) {
            iterator.remove();
        }

    } else if (obj instanceof Map) {
        Map temp = (Map) obj;
        if (temp == null || temp.isEmpty()) {
            iterator.remove();
        }

    } else if (obj instanceof Object[]) {
        Object[] array = (Object[]) obj;
        if (array == null || array.length <= 0) {
            iterator.remove();
        }
    } else {
        if (obj == null) {
            iterator.remove();
        }
    }
}

输出的结果：