线程安全

public class DemoClass4ThreadSafe {
    public static void main(String[] args) {
        //TODO 线程安全
        User18 user18 = new User18();

        Thread t1 = new Thread(()->{
            user18.name = "lisi";
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
            System.out.println("t1=" + user18.name);
        });

        Thread t2 = new Thread(()->{
            user18.name = "wangwu";
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
            System.out.println("t2=" + user18.name);
        });

        t1.start();
        t2.start();
        System.out.println("main 打印数据.");


        /*
        * 打印结果：
          main 打印数据.
          t1=wangwu
          t2=wangwu
        *
        *如果这样写：
        * t2.start();
        * t1.start();
        *
        * 打印结果：
        * main 打印数据.
        * t1=lisi
        * t2=lisi
        * */
    }

}

class User18{
    public String name;
}