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https://issues.apache.org/jira/browse/DERBY-3911?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12688514#action_12688514
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Kathey Marsden commented on DERBY-3911:
---------------------------------------
Thanks Tiago for looking at in Ganymede. I will assume then that it is just an
Eclipse bug. Someday I will be brave and upgrade my Eclipse.
It is interesting though, in playing with this I was able to make a program
that hides a ClassCastException with an NPE in the finally clause. This one
actually didn't give me a warning in Eclipse. It is an interesting case to
think about when doing complex operations in finally blocks.
public class FinallyTest {
public static void main(String[] args) throws Exception {
System.out.println(makeMyString());
}
private static String makeMyString() throws Exception {
String myString = null;
try {
myString = (String) new Object();
} finally {
// we lose our ClassCastException
release();
System.out.println("Finished finally");
}
return myString;
}
private static void release() throws Exception {
Object aNullObject = null;
System.out.println(aNullObject.toString());
}
}
> java FinallyTest
Exception in thread "main" java.lang.NullPointerException
at FinallyTest.release(FinallyTest.java:25)
at FinallyTest.makeMyString(FinallyTest.java:16)
at FinallyTest.main(FinallyTest.java:6)
> BTreeController.reclaim_deleted_rows() may hide exceptions
> ----------------------------------------------------------
>
> Key: DERBY-3911
> URL: https://issues.apache.org/jira/browse/DERBY-3911
> Project: Derby
> Issue Type: Bug
> Components: Store
> Affects Versions: 10.5.0.0
> Reporter: Knut Anders Hatlen
> Assignee: Knut Anders Hatlen
> Priority: Minor
> Fix For: 10.5.0.0
>
> Attachments: derby-3911.diff
>
>
> BTreeController.reclaim_deleted_rows() contains this piece of code:
> catch (java.lang.ClassCastException cce)
> {
> // because we give up the latch on the leaf before entering this
> // routine, the page might change from a leaf to branch. If that
> // happens this routine will get a ClassCastException, and we
> // just give up trying to reclaim space.
> }
> finally
> {
> if (controlRow != null)
> controlRow.release();
> return(purged_at_least_one_row);
> }
> It intentionally hides ClassCastExceptions, but it also unintentionally hides
> all other exceptions because of the return statement in the finally clause.
> Some related discussions can be found in DERBY-3216 and DERBY-3905.
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