集合遍历iterator 和 listiterator 用法

一、iterator 用法：

Collection collection = new ArrayList();
		collection.add("s1");
		collection.add("s2");
		collection.add("s3");
		
		Iterator iterator = collection.iterator();//得到一个迭代器
		while(iterator.hasNext()){
			Object object = iterator.next();
			System.out.println("iterator="+object);
		}
		if(collection.isEmpty()){
			System.out.println("collection is Empty");
		}else{
			System.out.println("collection  not is Empty"+"长度："+collection.size());
			
			Iterator iterator2 = collection.iterator();
			while(iterator2.hasNext()){
				Object object = iterator2.next();
				System.out.println("remove:" + object);
				//collection.remove("s1");
				//iterator2.remove("s2");
				iterator2.remove();
			}
			Iterator iterator3 = collection.iterator();
			while(iterator3.hasNext()){//查看是否还有元素
				System.out.println("还有元素！！！");
			}
			if(collection.isEmpty()){
				System.out.println("collection is Empty");
			}
		}

 


二、listitrator用法：

List list = new ArrayList();
list.add("aaaa");
list.add("bbbb");
list.add("cccc");
list.add("dddd");
System.out.println("下标0开始：" + list.listIterator(0).next());
System.out.println("下标1开始：" + list.listIterator(1).next());
System.out.println("子列表List  1-4 :" + list.subList(1, 4));// 子列表

ListIterator listIterator = list.listIterator();// 默认从0下标
//listIterator.add("ssss");
/*
* while(listIterator.hasPrevious()){ listIterator.previous();
* System.out
* .println("next Index="+listIterator.nextIndex()+",Object="+listIterator
* .next()); }
*/
while (listIterator.hasNext()) {
System.out.println("next Index=" + listIterator.nextIndex()
+ ",Object=" + listIterator.next());
}

ListIterator listIterator2 = list.listIterator();
listIterator2.next();
listIterator2.set("oooo");
ListIterator listIterator3 = list.listIterator(list.size());
while (listIterator3.hasPrevious()) {
System.out.println("previous Index="
+ listIterator3.previousIndex() + ",Object="
+ listIterator3.previous());
}