[ http://issues.apache.org/jira/browse/DERBY-668?page=all ]
Bryan Pendleton updated DERBY-668:
----------------------------------
Attachment: derby-668-3.diff
Hi Kathey, please consider this most recent patch. I've reverted the handling
of db2jcc_license_c.jar back to the pre-patch behavior, to wit: if we find
db2jcc_license_c.jar in the classpath, and if we are also able to load some
version of the DB2Driver class or the DB2Version class, then we display the
db2jcc_license_c.jar file that we found in the classpath, and we also display
the version number information that we fetched from DB2Driver/DB2Version.
Here's a bunch of the various tests I ran; in all the cases, I think that the
output of the new SysInfo is correct, but I'd like you to confirm my results,
please :)
1, 2) java -cp derby.jar:derbytools.jar sysinfo [-cp]
3, 4) java -cp derby.jar:derbytools.jar:db2jcc.jar sysinfo [-cp]
5, 6) java -cp derby.jar:derbytools.jar:db2jcc.jar:db2_license_c.jar sysinfo
[-cp]
7, 8) java -cp derby.jar:derbytools.jar:db2_license_c.jar sysinfo [-cp]
9, 10) (with db2jcc.jar in $JAVA_HOME/jre/lib/ext), java -cp
derby.jar:derbytools.jar:db2_license_c.jar sysinfo [-cp]
Cases (7) and (8) are particularly interesting. Both the current sysinfo, and
the one with my patch, print no information about db2jcc_license_c.jar if we
cannot load any version of the DB2Driver or DB2Version classes. I think this is
reasonable, but I'd like to hear your opinion on this.
An alternate implementation would be, as you suggested in your comment, to
print a line for db2jcc_license_c.jar in this case, but don't print any version
information. I guess I don't know how important this is. In your comment, you
noted that the primary user mistake was to have db2jcc.jar, but not
db2jcc_license_c.jar, rather than vice-versa, so I don't know if it's worth
adding a bunch more code to try to do something useful about the case where we
have db2jcc_license_c.jar in the classpath, but NOT db2jcc.jar. Please tell me
what you think.
thanks,
bryan
> SysInfo can give misleading information when JDBC jars are loaded from
> jre/lib/ext
> ----------------------------------------------------------------------------------
>
> Key: DERBY-668
> URL: http://issues.apache.org/jira/browse/DERBY-668
> Project: Derby
> Type: Bug
> Components: Build tools
> Versions: 10.1.1.0
> Reporter: Bryan Pendleton
> Priority: Minor
> Attachments: Derby-668.diff, derby-668-2.diff, derby-668-3.diff
>
> There is a section in the SysInfo tool's output titled "Derby Information",
> which prints location and version information for the major Derby jars. Here
> is an example of that output:
> --------- Derby Information --------
> JRE - JDBC: J2SE 1.4.2 - JDBC 3.0
> [/home/bpendleton/src/derby-subversion/trunk/jars/insane/derby.jar] 10.2.0.0
> alpha - (315052M)
> [/home/bpendleton/src/derby-subversion/trunk/jars/insane/derbytools.jar]
> 10.2.0.0 alpha - (315052M)
> [/home/bpendleton/src/derby-subversion/trunk/jars/insane/derbynet.jar]
> 10.2.0.0 alpha - (315052M)
> [/home/bpendleton/src/derby-subversion/trunk/jars/insane/derbyclient.jar]
> 10.2.0.0 alpha - (315052M)
> [/home/bpendleton/downloads/derby/db2jcc/lib/db2jcc.jar] 2.4 - (17)
> [/home/bpendleton/downloads/derby/db2jcc/lib/db2jcc_license_c.jar] 2.4 - (17)
> Unfortunately, this tool can be fooled if you arrange for one of these jar
> files to be loaded from a magic location like $JAVA_HOME/jre/lib/ext.
> For example, I had (accidentally) placed an old version of db2jcc.jar into
> $JAVA_HOME/jre/lib/ext. When I ran SysInfo, it printed out:
> --------- Derby Information --------
> JRE - JDBC: J2SE 1.4.2 - JDBC 3.0
> [/home/bpendleton/src/derby-subversion/trunk/jars/insane/derby.jar] 10.2.0.0
> alpha - (315052M)
> [/home/bpendleton/src/derby-subversion/trunk/jars/insane/derbytools.jar]
> 10.2.0.0 alpha - (315052M)
> [/home/bpendleton/src/derby-subversion/trunk/jars/insane/derbynet.jar]
> 10.2.0.0 alpha - (315052M)
> [/home/bpendleton/src/derby-subversion/trunk/jars/insane/derbyclient.jar]
> 10.2.0.0 alpha - (315052M)
> [/home/bpendleton/downloads/derby/db2jcc/lib/db2jcc.jar] 1.0 - (581)
> [/home/bpendleton/downloads/derby/db2jcc/lib/db2jcc_license_c.jar] 1.0 - (581)
> However, the "1.0 (581)" information actually came from
> $JAVA_HOME/jre/lib/ext/db2jcc.jar, NOT from
> /home/bpendleton/downloads/derby/db2jcc/lib/db2jcc.jar.
> It would be nice if SysInfo could detect the difference between a jar file
> being loaded via the application class loader using $CLASSPATH, and a jar
> file being loaded via the system class loader using JDK library extensions.
> To reproduce the problem, simply:
> 1) Place an older version of db2jcc.jar into $JAVA_HOME/jre/lib/ext
> 2) Place a newer version of db2jcc.jar into your $CLASSPATH
> 3) Run SysInfo. You will see that it prints the name of the jarfile from
> $CLASSPATH, but the version info from the JDK copy.
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