new Thread(() -> { new Thread(() -> { try { Thread.sleep(1000); } catch (InterruptedException e) { throw new RuntimeException(e); } System.out.println(1); }).start(); try { Thread.sleep(2000); } catch (InterruptedException e) { throw new RuntimeException(e); } System.out.println(2); }).start(); D选项, java 完全没有问题啊。