Re: jTDS JDBC driver with IBM i 7.1 using JDBCR4

[Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>]

Hello René,

The important thing for this is to know what error message is showing on 
your display.  I'm not sure if we are seeing the whole message, since it 
starts with "at", which looks like something from the middle of the 
stack dump.

Can you please try running your application like this:

1) Start with a fresh session (SIGNOFF, then SIGNON to start a fresh 
session)

2) Type OVRPRTF FILE(STDOUT) TOFILE(QSYSPRT) HOLD(*YES) OVRSCOPE(*JOB)

3) Run your program.

4) Sign off.

This should cause the error messages to go to a spooled file instead of 
your display, and the spooled file should contain the entire message.

From the part you did have, it looks like UnsupportedClassVersionError 
-- this means that the version of the Java class you are using is not 
compatible with the version of the JVM you are running.  It's not clear 
to me if this is the right message, however, since it appears in the 
middle of the output you sent instead of at the start.

Also, not sure that I would set a CLASSPATH in a subprocedure...?   Keep 
in mind that the first time RPG uses Java in a given job, it loads the 
JVM into memory, and the CLASSPATH is only read at that time.  That 
means that if you run your subprocedure in a job where the JVM has 
already been loaded (from running any prior Java code) it will not check 
CLASSPATH a second time, so any changes to the CLASSPATH will be 
ignored.  (Until the job is ended/restarted.)


On 11/14/2014 3:16 PM, René A Valencourt wrote:
> This question is for Scott Klement, or anyone else who may have solved
> something like this...
>
> We have a new Power 8 IBM i running v7r1.  QShell tells me that we are
> running Java version "1.6.0" (which I guess is Java 6).
>
> java version "1.6.0"
> Java(TM) SE Runtime Environment (build pap3260sr16-20140418_01(SR16))
> IBM J9 VM (build 2.4, JRE 1.6.0 IBM J9 2.4 OS/400 ppc-32
> jvmap3260sr16-20140418_01 (JIT enabled, AOT enabled)
> J9VM - 20140416_196573
> JIT  - r9_20130920_46510ifx5
> GC   - GA24_Java6_SR16_20140416_1614_B196573)
> JCL  - 20140406_01
>
> I want to query a MS SQL Server 2005 database running on a Windows server
> from an RPG ILE program.  I created a program based on mssqltest.rpgle that
> Scott Klement made available.  I created an IFS directory called /javasql
> and put various driver .jar files there:
> ·         sqljdbc.jar
> ·         jtds-1.2.5.jar
> ·         jtds-1.2.6.jar
> ·         jtds-1.2.7.jar
> ·         jtds-1.2.8.jar
> ·         jtds-1.3.0.jar
> ·         jtds-1.3.1.jar
>
> When I specify Microsoft's driver this works every time.  Over the last
> couple of days, 'jtds-1.2.5.jar' has worked for me several dozen times (the
> later versions all got either the "major version" or "major-minor version"
> error).  Now today only the Microsoft driver works.
>
> I believe that the only difference be that at day's end yesterday I made
> changes in my program to put the code that checks and alters the CLASSPATH
> variable into a subprocedure, and I put the code that opens the JDBC
> connection into another subprocedure.  However, I'm not sure that this could
> cause this problem, and the program appears to run correctly with expected
> values in the variables.
>
> Before I run my program, QShell shows no CLASSPATH variable, afterwards
> there is one, so I know that code works:
>
> CLASSPATH=.::/javasql/jtds-1.2.5.jar
>
> My program's OpenJDBCconnection subprocedure calls the JDBC_ConnProp
> subprocedure inside the JDBCR4 service program.  Through RDi debug, I could
> see that just before the execution of 'new_Driver' subprocedure in JDBCR4,
> the path to the Driver class was set as expected
> ('net.sourceforge.jtds.jdbc.Driver'), and the URL also
> ('jdbc:jtds:sqlserver://172.18.120.21:1433'), though the program never gets
> to use it if it can't instantiate the driver...
>
> // Find & Instantiate Driver
>
>     drv = new_Driver(drivname);
>     if (drv = *NULL);
>       jdbc_end_object_group();
>       return *NULL;
>     endif;
>
> The program fails inside the JDBCR4 "new_Driver" subprocedure, at this code:
>
> cls = FindClass(env: drv_name);
> if (jni_CheckError(*omit));
>      return *NULL;
> endif;
>
> The value of 'drv_name' just before getting translated to ASCII was
> 'net/sourceforge/jtds/jdbc/Driver'.
>
> With the failure to instantiate the driver I get this display in my IBM i
> session:
>
>          at java.lang.ClassLoader.loadClass(ClassLoader.java:643)
> Exception in thread "main" java.lang.UnsupportedClassVersionError:
> JVMCFRE003 bad major version; class=net/sourceforge/jtds/jdbc/Driver,
> offset=6
>          at java.lang.ClassLoader.defineClass(ClassLoader.java:287)
>          at
> java.security.SecureClassLoader.defineClass(SecureClassLoader.java:74)
>          at java.net.URLClassLoader.defineClass(URLClassLoader.java:540)
>          at java.net.URLClassLoader.defineClass(URLClassLoader.java:451)
>          at java.net.URLClassLoader.access$300(URLClassLoader.java:79)
>          at java.net.URLClassLoader$ClassFinder.run(URLClassLoader.java:1038)
>          at
> java.security.AccessController.doPrivileged(AccessController.java:362)
>          at java.net.URLClassLoader.findClass(URLClassLoader.java:429)
>          at sun.misc.Launcher$ExtClassLoader.findClass(Launcher.java:281)
>          at java.lang.ClassLoader.loadClass(ClassLoader.java:677)
>          at java.lang.ClassLoader.loadClass(ClassLoader.java:669)
>          at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:358)
>          at java.lang.ClassLoader.loadClass(ClassLoader.java:643)
>
> As I mentioned, Microsoft's driver works without fail, and the jTDS 1.2.5
> driver was working yesterday!
>
> René A Valencourt, CCP, MCTS
> Senior Programmer/Analyst
> IS Department
> CTB
> CTB, Inc.
> A Berkshire Hathaway Company
>
>
> Re: Quick JDBCR4 questions
>
>    _____
>
>
>   <http://archive.midrange.com/rpg400-l/201402/msg00061.html> -
> *	Subject: Re: Quick JDBCR4 questions
> *	From: Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>
> *	Date: Thu, 13 Feb 2014 14:51:37 -0600
> *	List-archive: <http://archive.midrange.com/rpg400-l>
> *	List-help: <mailto:rpg400-l-request@xxxxxxxxxxxx?subject=help>
> *	List-id: "RPG programming on the IBM i \(AS/400 and iSeries\)"
> <rpg400-l.midrange.com>
> *	List-post: <mailto:rpg400-l@xxxxxxxxxxxx>
> *	List-subscribe:
> <http://lists.midrange.com/mailman/listinfo/rpg400-l>,
> <mailto:rpg400-l-request@xxxxxxxxxxxx?subject=subscribe>
> *	List-unsubscribe:
> <http://lists.midrange.com/mailman/listinfo/rpg400-l>,
> <mailto:rpg400-l-request@xxxxxxxxxxxx?subject=unsubscribe>
>
> fixed <http://archive.midrange.com/rpg400-l/201402/msg00061.html>
>    _____
>
> Chuck,
>
> JDBCR4 works with Java 1.3 or higher. However, the individual database
> drivers also have their requirements.
>
> In your case, it sounds like you are using the jTDS driver (for Microsoft
> SQL Server).
>
> If I recall correctly the version of Java that jTDS requires varies with the
> version of jTDS that you're using. jTDS 1.3.x requires Java 7, and jTDS
> 1.2.x works with older versions of Java.
>
> So, you'll either want to install Java 7 (sometimes called "1.7") and if
> necessary, set your JAVA_HOME environment variable to point to it... or get
> an older version of jTDS. I used 1.2.5 successfully with older JVMs.
>
> Good luck!