遍历 Vector 的两种方法：

Iterator iter = v.iterator();

while(iter.hasNext()){

StudentVo value = (StudentVo)iter.next();

System.out.println(value);

}

Enumeration enu = v.elements();

while(enu.hasMoreElements()){

StudentVo value = (StudentVo)enu.nextElement();

System.out.println(value);

}