Thread_project/Thread_module/src/Thread_safe_package/MyThread.java

package Thread_safe_package;

public class MyThread extends Thread {
    static int ticket = 0;

    //锁对象：一定要是唯一的
    static Object obj = new Object();


    @Override
    public void run() {
        while (true) {
            //同步代码块---锁对象：MyThread.class | obj
            synchronized (MyThread.class) {
                if (ticket < 100) {
                    try {
                        Thread.sleep(10);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }

                    ticket++;
                    System.out.println(getName() + "正在卖第" + ticket + "张票");
                } else {
                    break;
                }
            }
        }
    }
}