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利用cas算法实现。基于乐观锁。如果值发生冲突。加入异步线程递归进行抢（设置递归次数。防止死循环）

1、创建ThreadUtils类

/** * 线程副本，保证数据 */public class ThreadUtils {    private static ThreadLocal
   
     threadLocal;    static{        threadLocal = new ThreadLocal();    }    public static void set(int value){        threadLocal.set(value);    }    public static Integer get(){        return threadLocal.get();    }}
   

2、创建CasUtils类

/** * 基于cas原理实现高并发 */public class CasUtils implements Runnable{    /**      * 私有内部类创建单例     */    private static class AtomicHolder{        private static volatile AtomicInteger s = new AtomicInteger(ThreadUtils.get());    }    /**     * 线程池     */    private  static ThreadPoolExecutor ex;    static {         ex = new ThreadPoolExecutor(                10,10,5,TimeUnit.SECONDS,                new ArrayBlockingQueue
   
    (1),                new ThreadPoolExecutor.DiscardOldestPolicy());    }    public CasUtils()throws Exception{        int value = ThreadUtils.get();        if(!AtomicHolder.s.compareAndSet(value,value)){            /**             * 此处对于未赋值的进行其他操作             */        }    }    @Override    public void run() {        System.out.println("我在抢票中..."+Thread.currentThread());        try {            int value = AtomicHolder.s.get();            int si = 0;            if(value-1>=0&&(si=AtomicHolder.s.decrementAndGet())>0){                /**                 * 涉及业务可以写入消息队列                 */                System.out.println("抢票成功..."+Thread.currentThread()+"========"+(si));            }else{                /*if(value-1<0){                    System.out.println("暂无票..."+Thread.currentThread()+"========"+(si));                    return;                }*/                ex.execute(new Runnable() {                    @Override                    public void run() {                        System.out.println("抢票循环..."+Thread.currentThread());                        boolean isSubmit = true;                        //设置抢票循环次数。                        int time = 0;                        while(isSubmit){                            ++time;                            int value = AtomicHolder.s.get();                            //超过10次结束                            if(time>=10){                                System.out.println("抢票结束【未抢到】..."+Thread.currentThread());                                isSubmit = false;                                break;                            }                            if(value-1>=0&&AtomicHolder.s.decrementAndGet()>0){                                /**                                 * 涉及业务可以写入消息队列                                 */                                isSubmit = false;                                System.out.println("抢票成功..."+Thread.currentThread());                            }                            try {                                Thread.sleep(200);                            } catch (InterruptedException e) {                                e.printStackTrace();                            }                        }                    }                });            }            Thread.sleep(2000);        } catch (InterruptedException e) {            e.printStackTrace();        }    }}
   

3、执行public static void main(String[] args) throws Exception {    for(int i=0;i<100;i++){        ThreadUtils.set(10);        new Thread( new CasUtils()).start();    }}

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