Greg,
How is wwPOIFS getting created? Is it null? How about newPOIFSFileSystem? I've never used POI from RPG (but I do use POI) but I do quite a bit of Java programming and any of these being null can cause a null pointer exception.
Matt
-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Fleming, Greg (ED)
Sent: Friday, November 30, 2007 8:14 AM
To: RPG programming on the AS400 / iSeries
Subject: RE: Java error when updating existing Excel spreadsheets using HSSF
Scott,
I guess what I'm looking for at this point is some direction on what I
can do to find more detail.
When I debug, I step through the upddemo program and step into the
hssf_open() procedure,
Then when I step into the "wwPOIFS = new_POIFSFileSystem(wwFile);"
statement the program terminates.
Is there a way to debug the Java program itself to see what's going on
in more detail ?
The wwFile variable doesn't appear to be null at the time (I think it
showed up as 8 in debug), so I don't know what "null object" is being
passed, nor to what "non-static method" it is being passed.
As you can see, the job log isn't terribly informative, either.
I don't reckon it was necessary, but just for craps and giggles I went
ahead and ran the CRTVJVAPGM command on the POI 3.0.1. class (optimize
40), but that didn't make any difference either.
Thanks again for any direction or suggestions you can provide.
And if you can't, then you can't. We have a really crappy workaround we
can implement if we can't get your code working. I understand there is
only so much you can do without being here, and I seriously doubt I can
get the boss to fly you down to South Florida. ;->
Greg
|-----Original Message-----
|From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-
|bounces@xxxxxxxxxxxx] On Behalf Of Scott Klement
|Sent: Thursday, November 29, 2007 8:14 PM
|To: RPG programming on the AS400 / iSeries
|Subject: Re: Java error when updating existing Excel spreadsheets using
|HSSF
|
|Hi Greg,
|
|Is there some way I can reproduce this error on my box? I'm really
|struggling to determine what, specifically, is going on.
|
|So I guess I'm saying that either you need to debug the code in detail
|to figure out what's going on, or you need to tell me how to reproduce
|the problem so I can debug the code in detail. Right now I just don't
|have any information about the problem other than "it doesn't work and
|the JVM crashes." Which is just a bit too broad for me to
|troubleshoot...
|
|
|
|
|Fleming, Greg (ED) wrote:
|> Scott,
|>
|> I downloaded your latest, installed the 3.0.1 POI, changed the
upddemo
|> program to include the "if book = *null" code you mentioned below. It
|> never gets to the "if" block, though, because the error occurs inside
|of
|> the hssf_open procedure and the program terminates immediately.
|>
|> I still get the same error, but now it happens on the next line "
|> wwPOIFS = new_POIFSFileSystem(wwFile);" which seems odd, given that
|this
|> line is inside a monitor block. As soon as I step into the line,
|> program terminates.
|>
|> There aren't any messages prior to the JVM termination in the job
log.
|> As you can see in this snippet, it goes straight from calling the
|> upddemo program to crashing:
|>
|> *NONE Request 11/29/07 13:23:23.598896
|> QWTSCSBJ *N QCMD QSYS 0189
|> Message . . . . : -CALL
|> PGM(UPDDEMO)
|> MCH74A5 Escape 40 11/29/07 13:23:30.047264
|> realcftrap2 001728 QJVAJNI QSYS *STMT
|> To module . . . . . . . . . :
|> QJVAJNI
|> To procedure . . . . . . . :
|> CallVoidMethodA
|> Statement . . . . . . . . . :
1
|> Message . . . . : The Java
|> Virtual Machine has ended.
|> Cause . . . . . : Java Virtual
|> Machine 1 has ended because of reason 2. The
|> reason codes are defined as
|> follows: 01- A Java program called the
|> java.lang.System.exit method
|with
|> a zero status code. 02- A Java program
|> called the
|java.lang.System.exit
|> method with a non zero status code of 134.
|>
|> Again as before, there is also a spooled file produced from the job
|> containing this text:
|> FATAL ERROR in native method: native code passed a null object to a
|> non-static method
|> java.lang.Throwable
|>
|> Anything else I can look at to find some kind of error messages prior
|to
|> the inglorious death of the JVM ?
|>
|> Thanks again.
|>
|> Greg
|>
|>
|> |-----Original Message-----
|> |From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-
|> |bounces@xxxxxxxxxxxx] On Behalf Of Scott Klement
|> |Sent: Thursday, November 29, 2007 12:39 PM
|> |To: RPG programming on the AS400 / iSeries
|> |Subject: Re: Java error when updating existing Excel spreadsheets
|using
|> |HSSF
|> |
|> |Greg,
|> |
|> |You are using an outdated copy of HSSFR4. Please download and use
|the
|> |current one. I know that your copy is outdated because the
|> |FileInputStream vs FileOutputStream thing was corrected in Aug 2006
-
|-
|> |more than a year ago.
|> |
|> |The most recent version can be found in the following article
|> |(Systeminetwork.com membership required, but a free "associate"
|> |membership will work):
|> |
http://www.systeminetwork.com/article.cfm?id=55032
|> |
|> |Having said that, it's important to understand that RPG's O=Object
|data
|> |type aren't the actual Java objects. They're just REFERENCES to the
|> |objects. Under the covers, they're just numbers -- and the numbers
|are
|> |used by the JVM to locate the actual object, which always resides in
|> the
|> |JVM itself. So whether I coded FileInputStream or FileOutputStream
|> |doesn't really matter, as long as the number does actually refer to
a
|> |FileInputStream object in the JVM. The reason that code made it
|into
|> |wide use is because it worked, despite being coded incorrectly,
|because
|> |it still referred to the right type of object.
|> |
|> |
|> |Regarding the "JVM ended, Reason code 2" error:
|> |
|> |That almost always happens when you pass a *NULL object to a Java
|> |routine. Like I said, RPG's O=Object data type is only a number
that
|> |refers to a Java object. If you set that number to *NULL (which
|under
|> |the covers is zero) the JVM will be trying to refer to an object
that
|> |doesn't exist, and that causes it to become confused and end
|> abnormally.
|> |
|> |Note that hssf_open() returns *NULL if it can't open the file. Your
|> |code is SUPPOSED to check for that *NULL, and either try again, or
|end
|> |the program, or whatever it needs to do, when it encounters the
|*NULL.
|> |What it should NOT do is pass that *NULL object to another Java
|> routine.
|> | And I suspect that this is what it's doing.... it's not checking
|for
|> |the *NULL, and is proceeding as if everything is fine. And when
Java
|> |gets that *NULL value, it crashes the JVM.
|> |
|> |So you can fix that by changing your code to something like this:
|> |
|> | book = HSSF_open('/path/to/whatever.xls');
|> | if (book = *null);
|> | *inlr = *on;
|> | return;
|> | endif;
|> |
|> |So... if the open failed, the program does not try to manipulate the
|> |workbook (since it was never loaded), it just ends.
|> |
|> |That'll stop the JVM from crashing, but won't cause the HSSF_open()
|> |routine to load your spreadsheet. There should be earlier messages
|in
|> |the job log (earlier than that JVM ended thing) that explain why the
|> |file didn't open...
|> |
|> |
|> |
|> |Fleming, Greg (ED) wrote:
|> |> Scott,
|> |>
|> |> Some further info may help us narrow this down.
|> |>
|> |> In debug, the error appears to occur in the HSSF_Open procedure at
|> |line
|> |> 1559
|> |> wwFile = new_FileInputStream(wwStr);
|> |>
|> |> I had read on another list somewhere that the preceding definition
|on
|> |> line 1553:
|> |> D wwFile s like(jFileOutputStream)
|> |> Was in error and should be corrected to:
|> |> D wwFile s like(jFileInputStream)
|.
|> |>
|> |> I did this, recompiled the module and re-created the service
|program,
|> |> then rebound
|> |> The upddemo program. But I still get the same error either way.
|--
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