package Collection;import java.util.LinkedList;/*LinkedList:特有的方法addFirst()/addLast();getFirst()/getLast();removeFirst()/removeLast();若链表为空，抛出 没有这个元素异常/NoSuchElementException但是 JDK1.6 版本以后出现了替代方法:offerFirst()/offerLast();peekFirst()/peekLast()pollFirst()/pollLast():若链表为空，则返回null*/public class LinkListDemo{	public static void main(String[] args)	{		LinkedList
      
        link = new LinkedList
       
        ();				link.addFirst("Java01");		link.addFirst("Java02");		link.addFirst("Java03");		link.addFirst("Java04");				sop(link); 		// [Java04, Java03, Java02, Java01]		/*		get 方法只取元素		remove 方法取完元素，还删除		*/				/*		sop(link.getFirst());		sop(link.getLast());		sop(link.removeFirst());		sop(link.removeLast());				sop("size: "+link.size());		*/				while (!link.isEmpty())		{			sop(link.removeFirst());		}	}		public static void  sop(Object obj)	{		System.err.println(obj);	}}package Collection;import java.util.LinkedList;/*使用LinkedList 模拟一个堆栈或者队列数据结构。  堆栈：先进后出 队列：先进先出 */class DuiLie{	private LinkedList link;	DuiLie()	{		link = new LinkedList();	}		public void myAdd(Object obj)	{		link.addFirst(obj);	}	public Object myGet()	{		return link.removeLast();	}		public boolean isNull()	{		return link.isEmpty();	}	}public class LinkListTest{	public static void main(String[] args)	{		DuiLie dl = new DuiLie();		dl.myAdd("Java01");		dl.myAdd("Java02");		dl.myAdd("Java03");		dl.myAdd("Java04");				// System.out.println(dl.myGet());				System.out.println("============");				while (!dl.isNull())		{			System.out.println(dl.myGet());		}	}}