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https://issues.apache.org/jira/browse/DERBY-2472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12497266
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Knut Anders Hatlen commented on DERBY-2472:
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The patch that replaced StandardException.setNestedException() with
Throwable.initCause() may have introduced a problem in
GenericLanguageConnectionContext.dropAllDeclaredGlobalTempTables() and
BasicDependencyManager.coreInvalidateFor(). These two methods accumulate
StandardExceptions which are thrown from within a loop, and the exceptions are
re-thrown when the loop has ended. The exception that is re-thrown is the last
exception that was caught, and it has all previously caught exceptions as its
cause. The code that accumulates the exceptions looks like this:
} catch (StandardException e) {
e.initCause(topLevelStandardException);
topLevelStandardException = e;
}
The problem is that initCause() can only be called once on a Throwable, so if
the StandardException already has a cause, initCause() will throw an
IllegalStateException. The old code would not fail if this happened since
setNestedException() would happily overwrite any existing nested exception.
One solution is to call initCause() on the exception's cause (or the cause of
the cause, etc) if it has one. However, this wouldn't work if the last
exception in the chain has been initialized with null as cause, since null also
blocks subsequent calls to initCause(). Therefore, I suggest that we change the
code so that it tries to chain the exceptions as suggested above, but if the
StandardException cannot add a new exception to its chain, a new exception is
created with the same SQL state, message and stack trace, but with no cause,
and the clone is inserted into the chain instead.
> Use Throwable.initCause() to improve error reporting
> ----------------------------------------------------
>
> Key: DERBY-2472
> URL: https://issues.apache.org/jira/browse/DERBY-2472
> Project: Derby
> Issue Type: Improvement
> Components: JDBC, Miscellaneous
> Affects Versions: 10.3.0.0
> Reporter: Kristian Waagan
> Assigned To: Knut Anders Hatlen
> Priority: Minor
> Attachments: derby-2472_initial_patch.diff, embedsqlexception.diff,
> embedsqlexception.stat, seenext.diff, seenext.stat, setStackTrace-v2.diff,
> setStackTrace.diff, standardexception.diff, standardexception.stat
>
>
> As Derby has moved to J2SE 1.4, Throwable.initCause() can now be used to
> improve error reporting.
> As stated in the initial commit (that was backed out, see below):
> 'Set Throwable.initCause() in a couple of locations at the JDBC level where
> we setup nested SQLExceptions.
> This means that automatically the stack trace for a database failed to start
> includes the reason
> for the failure, rather than just "see next exception". This is a great help
> when running
> JUnit tests and getting failures to start a database.'
> The initial commit was backed out because it broke numerous tests under JDK
> 1.6, and the author indicated he had no time to investigate.
> The patch caused no failures when running the tests with Java SE 5.0.
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