用迭代器取出ArrayList集合集合中的元素。(用for和while正反向遍历)

import java.util.*;
class ListDemo1
{
public static void main(String[] args)
{
ArrayList a=new ArrayList();
a.add("java01");
a.add("java02");
a.add("java03");
ListIterator t=a.listIterator();
for (; t.hasNext(); )
{
System.out.println(t.next());
}
for ( ;t.hasPrevious() ; )
{
System.out.println(t.previous());
}
/*ListIterator t=a.listIterator();
while (t.hasNext())
{
System.out.println(t.next());
}
while (t.hasPrevious())
{
System.out.println(t.previous());
}*/

}
}
/*for (int x=0;x<v.size() ;x++ )
{
System.out.println(v.get(x));
}*/（不用迭代器，对ArrayList集合中元素的取出）