在 Java 中為什么會出現 java.lang.IllegalStateException: cannot open system clipboard ？這是使用 Java 1.8.0_181 25.181-b13 在 Windows 上運行的java.lang.IllegalStateException: cannot open system clipboard    at sun.awt.windows.WClipboard.openClipboard(Native Method)    at sun.awt.datatransfer.SunClipboard.getClipboardFormatsOpenClose(SunClipboard.java:327)    at sun.awt.datatransfer.SunClipboard.isDataFlavorAvailable(SunClipboard.java:188)    at com.jthink.songkong.ui.startdialog.editsongs.EditSongsTable$PasteAction$1.flavorsChanged(EditSongsTable.java:170)    at sun.awt.datatransfer.SunClipboard$1SunFlavorChangeNotifier.run(SunClipboard.java:441)    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)    at java.awt.EventQueue.access$500(EventQueue.java:97)    at java.awt.EventQueue$3.run(EventQueue.java:709)    at java.awt.EventQueue$3.run(EventQueue.java:703)    at java.security.AccessController.doPrivileged(Native Method)    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)    at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)