public class SimpleLinkedQueue {class Node{public String v;public Node next;public Node(String v){this.v = v;}}Node init = new Node(null);Node head = init;Node tail = init;public void put(String v){Node node = new Node(v);tail.next = node;tail = node;}public String take(){
// 第一次实现,head 只是一个空的节点,不包含数据,head的next才是第一个数据节点 ，下面四行实现没考虑到
//      String v = head.v;
//      Node tempHead = head.next;
//      head = tempHead;
//      return v;/*** 第二次实现* 1. 取出第一个数据节点 * 2. 把head节点指针指向第一个数据节点， 并切断老的head 和 first的联系 , head ->/ first -> second ->...*  */Node oldHead = head;Node first = head.next;  //第一个数据节点String v = first.v;head = first;head.v = null;oldHead.next = null;return v;}public void readFromHead(){System.out.println("head is :" + head.v);Node n = head.next;while(n != null){System.out.println(n.v);n = n.next;}}public static void main(String args[]){SimpleLinkedQueue q = new SimpleLinkedQueue();for (int i = 0; i < 10; i++) {q.put("data-"+i);}System.out.println("take 1 : " + q.take());System.out.println("take 2 : " + q.take());q.readFromHead();}
}

// 未考虑线程安全,只做练习队列的写法
public class SimpleArrayQueue {public SimpleArrayQueue(){this(Integer.MAX_VALUE);}public SimpleArrayQueue(int length){list = new String[length];}private String[] list = null;  //队列private int take;  //take游标private int put;  //put游标private int count; //队列内元素数public void put(String e){if(count == list.length){System.out.println("队列满了,该清理了..,数据 " + e + " 被丢弃" );return;}list[put] = e;put++;count++;if(put == list.length)put = 0;}public String take(){if(count == 0){System.out.println("队列空了,还取个毛啊..");return null;}String e = list[take];list[take] = null;take++;count--;if(take == list.length)take = 0;return e;}public void read(){for(int i=0;i<list.length;i++){if(list[i] == null)continue;System.out.println("read : "+ i + " : " + list[i]);}}public static void main(String args[]){SimpleArrayQueue s = new SimpleArrayQueue(10);for(int i=0; i<8;i++){s.put("数"+i);}System.out.println("take 1 " + s.take());System.out.println("take 2 " + s.take());s.read();s.put("数***");s.put("数***1");System.out.println("take 3 " + s.take());s.put("数***2");s.read();}
}