public class PrintOddEvenSync {
    private static Integer count = 0;
   // private static Integer lock = 0;

    public static void main(String[] args) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                synchronized (count) {
                    System.out.println(Thread.currentThread().getName() + "获取锁");
                    while (count < 100) {
                        System.out.println(Thread.currentThread().getName() + "分析偶数：count=" + count);
                        if (count % 2 == 0) {
                            System.out.println("偶数：" + count);
                            count++;
                        }
                    }
                    System.out.println(Thread.currentThread().getName() + "释放锁");
                }
            }
        },"thread1:").start();

        new Thread(new Runnable() {
            @Override
            public void run() {
                synchronized (count) {
                    System.out.println(Thread.currentThread().getName() + "获取锁");
                    while (count < 100) {
                        System.out.println(Thread.currentThread().getName() + "分析奇数：count=" + count);
                        if (count % 2 == 1) {
                            System.out.println("奇数：" + count);
                            count++;
                        }
                    }
                    System.out.println(Thread.currentThread().getName() + "释放锁");
                }
            }
        },"thread2:").start();
    }
}

不使用count作为锁，代码是正常的，使用了count，synchronized就好像无效了，不清楚为什么，老师能解释一下吗