Hello! In sun.print.IPPPrintService.getIPPConnection(URL), there is a bug with class casting: see
<URL:http://hg.openjdk.java.net/jdk6/jdk6/jdk/file/5672a2be515a/src/solaris/classes/sun/print/IPPPrintService.java>, lines 1556–1565 for JDK 6, and <URL:http://hg.openjdk.java.net/jdk7/swing/jdk/file/d449b91c56b6/src/solaris/classes/sun/print/IPPPrintService.java>, lines 1563–1572 for JDK 7. The buggy code is: public static HttpURLConnection getIPPConnection(URL url) { HttpURLConnection connection; try { connection = (HttpURLConnection)url.openConnection(); } catch (java.io.IOException ioe) { return null; } if (!(connection instanceof HttpURLConnection)) { return null; } If the call to openConnection returns a FileURLConnection (as it does on my system), that cannot be cast to an HttpURLConnection. The instanceof check happens too late in the code. What to do: either * catch a ClassCastException and return null from the catch block, or * use a variable of type URLConnection to store the result from openConnection(), and cast it to HttpURLConnection /after/ the block with the instanceof check. The problem occurs, because there are URLs like "file:/dev/null" in the list or URLs to try. They are retrieved from sun.print.CUPSPrinter.getAllPrinters() via sun.print.UnixPrintServiceLookup.refreshServices(). I assume this happens for printers that were auto-detected (e.g. via ZeroConf etc.) some time ago, but are not accessible at the moment), but I am not sure about that. Perhaps the CUPS system is improperly configured, but this should not cause Java applications to throw ClassCastExceptions. Regards -- Nico
