import java.util.concurrent.locks.Lock;import java.util.concurrent.locks.ReentrantLock;public class sequence {    private static final long ONE_STEP = 10;    private static final Lock LOCK = new ReentrantLock();    private static long lastTime = System.currentTimeMillis();    private static short lastCount = 0;    private static int count = 0;    @SuppressWarnings("finally")    public static String nextId()     {        LOCK.lock();        try {            if (lastCount == ONE_STEP) {                boolean done = false;                while (!done) {                    long now = System.currentTimeMillis();                    if (now == lastTime) {                        try {                            Thread.currentThread();                            Thread.sleep(1);                        } catch (java.lang.InterruptedException e) {                        }                        continue;                    } else {                        lastTime = now;                        lastCount = 0;                        done = true;                    }                }            }            count = lastCount++;        }        finally         {            LOCK.unlock();            return lastTime+""+String.format("%03d",count);         }    }    public static void main(String[] args)    {        //测试        for(int i=0;i<1000;i++)        {            System.out.println(nextId());        }            }}