The exception stack trace is incorrect as exception is saved and then thrower from a different place.

java.io.IOException: system clipboard data unavailable
at sun.awt.windows.WClipboard.getClipboardData(Native Method)
at sun.awt.datatransfer.ClipboardTransferable.fetchOneFlavor(ClipboardTransferable.java:118)
at sun.awt.datatransfer.ClipboardTransferable.<init>(ClipboardTransferable.java:97)
at sun.awt.datatransfer.SunClipboard.getContents(SunClipboard.java:147)