如果你的意思是关闭所有窗口后JVM没有正常退出，那么看以下几点:

If you mean that the JVM doesn't exit properly after closing all windows, then look at the following points:

• 检查所有窗口是否已正确处理，而不仅仅是简单地隐藏起来；其中包括由 Swing(或 AWT)作为无所有者对话框的所有者创建的不可见窗口.为此，您可以检查 Window.getWindows()
• 确保在处理完所有窗口后没有活动的Thread(守护进程除外)
• 确保您的应用程序不是由 Java Web Start 启动的，因为在这种情况下您必须调用 System.exit(0)(这是 JWS 的已知错误)

• check that ALL windows have been disposed properly, not just simply made invisible; that includes the invisible window created by Swing (or AWT) as the owner of ownerless dialogs. For this you can check Window.getWindows()
• make sure you have no active Thread (except daemons) after disposing of all windows
• ensure that your application was not launched by Java Web Start, because in this case you must call System.exit(0) (that's a known bug of JWS)

希望这有助于回答您的问题.

Hope this helps answer your question.

此外，最近还有这个SO问题关于垃圾收集摆动窗户.

Besides, there was also this SO question recently about garbage collection of Swing windows.