Java SE (Java Platform, Standard Edition)

Hi,
I wanted to understand how java uses the variable sun.nio.ch.bugLevel .. and what is the value that it needs to be set. searching for this variable gave me a result where some one has set -Dsun.nio.ch.bugLevel=1.4 as the jvm option.

ISSUE: I am randomly encountering a NullPointerException while calling Selector.open

CAUSE:
Here is the stack trace:

"java.lang.NullPointerException
at sun.nio.ch.Util.atBugLevel(Util.java:326)
at sun.nio.ch.SelectorImpl.<init>(SelectorImpl.java:40)
at sun.nio.ch.WindowsSelectorImpl.<init>(WindowsSelectorImpl.java:104)
at sun.nio.ch.WindowsSelectorProvider.openSelector(WindowsSelectorProvider.java:26)
at java.nio.channels.Selector.open(Selector.java:209)

This is cause due to a bug in java 1.5 (which has been fixed in Java 7)
http://bugs.sun.com/bugdatabase/view_bug.do;jsessionid=9ea0db6110bd136e5288fa753945f?bug_id=6427854
This bug has not yet been fixed in Java 1.5

Here is the excerpt from the java 7 code:
https://openjdk.dev.java.net/source/browse/openjdk/jdk/trunk/jdk/src/share/classes/sun/nio/ch/Util.java?rev=257&view=markup

// -- Bug compatibility --

private static volatile String bugLevel = null;

static boolean atBugLevel(String bl) { // package-private
if (bugLevel == null) {
if (!sun.misc.VM.isBooted())
return false;
String value = AccessController.doPrivileged(
new GetPropertyAction("sun.nio.ch.bugLevel"));
bugLevel = (value != null) ? value : "";
}
return bugLevel.equals(bl);
}

java -version "1.5.0_15"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_15-b04)
Java HotSpot(TM) Client VM (build 1.5.0_15-b04, mixed mode, sharing)





Thanks in advance


Vijay