Redhat FC6 Linux 2.6.19-1.2895.fc6 #1 SMP
Java HotSpot(TM) Client VM (build 1.6.0-b105, mixed mode, sharing)

Person reporting the bug is a Sun employee, but without
bugster access (###@###.###)

The following code produces the following exception:

java.lang.NullPointerException
       at sun.nio.ch.EPollSelectorImpl.wakeup(EPollSelectorImpl.java:170)
       at net.jxta.impl.endpoint.tcp.TcpTransport.stopApp(TcpTransport.java:841)

According to the API, a call to Selector.wakeup() is not required after calling Selector.close(), and arguably the call is not required, however EPollSelectorImpl should not throw an NPE.

       Thread temp = messengerSelectorThread;
       if (null != temp) {
           temp.interrupt();
           try {
               messengerSelector.close();
           } catch (IOException failed) {
               if (LOG.isLoggable(Level.SEVERE)) {
                   LOG.log(Level.SEVERE, "IO error occured while closing server socket", failed);
               }
           }
       }

       // in case interrupt did not wakeup the Selector
Line:841>>> messengerSelector.wakeup();