import java.util.concurrent.atomic.AtomicLong;

public class VolatileTest1 {

private static final AtomicLong THREAD1_COUNT = new AtomicLong(0);
private static final AtomicLong THREAD2_COUNT = new AtomicLong(0);

// static 变量 i
static volatile Integer i = 0;

public static void main(String[] args) throws Exception {

// 线程 1
Thread thread1 = new Thread(() -> {
synchronized (i) {
try {

i = 1;
Thread.sleep(100);
THREAD1_COUNT.incrementAndGet();
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
});

// 线程 2
Thread thread2 = new Thread(() -> {
synchronized (i) {
try {

i = 2;
Thread.sleep(100);
if (i == 1) {
System.out.println("1"); // 实际运行结果为 1
System.out.println("thread1 运行次数" + THREAD1_COUNT.get());
System.out.println("thread2 运行次数" + THREAD2_COUNT.get());
}
THREAD2_COUNT.incrementAndGet();
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
});

// 不断运行线程 1 和 2
while (true) {
new Thread(thread1).start();
new Thread(thread2).start();
}
}
}



要不你试试这个，，看看