Memory leak in sun.print.Win32PrintServiceLookup.notifyPrinterChange

Question

When I stop my Tomcat server in windows sometimes I have to wait long time, in these cases I got this warning:

org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [ROOT] appears to have started a thread named [Thread-6] but has failed to stop it. This is very likely to create a memory leak.
Stack trace of thread:
 sun.print.Win32PrintServiceLookup.notifyPrinterChange
 sun.print.Win32PrintServiceLookup.access$100(Unknown Source)
 sun.print.Win32PrintServiceLookup$PrinterChangeListener.run(Unknown Source)

The only printer-connected code in my web app is a reader of available printers with:

PrintService[] printServices = PrinterJob.lookupPrintServices();

Do you know how to avoid this problem?

Answer 1

That thread is started by Win32PrintServiceLookup itself , unless it thinks you are on Windows 98 , which it verifies by using system property os.name , so here is a funky (tentative) workaround:

String osName = System.getProperty("os.name");
if (osName.startsWith("Windows")) { // or SystemUtils.IS_OS_WINDOWS if you use commons-lang
    System.setProperty("os.name", "Windows 98");  // Pretend you're on Win98
}
PrinterJob.lookupPrintServices();
System.setProperty("os.name", osName); // Restore original value

I have not tested (no Windows system around today), so I just hope it still gets the list once. It also means you lose the ability to register changes of printers during the application lifetime.