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Hello again,
I tried something else a few minutes ago, and now it seems to be
working consistently. However, I am not sure WHY it works!
I changed the System.default.properties file in
/QIBM/UserData/Java400. It contained:
java.version=1.3
and I changed it to
java.version=1.4
I logged off, logged back on, tried it again, and it worked!
So, I went back and changed it back to
java.version=1.3
I logged off, logged back on, tried it again, and it still worked!
That is good that it works, BUT I don't know WHY it works... what is
going on here that I need to know about? Is there some sort of caching
that was messed up and changing the JVM version back and forth some how
fixed it or forced the cache to get flushed or something? I am seriously
confused here. Aaaaargh!
Dan Feather
dfeather@xxxxxxxxxxxxx
-----Original Message-----
From: java400-l-bounces@xxxxxxxxxxxx
[mailto:java400-l-bounces@xxxxxxxxxxxx] On Behalf Of Daniel Feather
Sent: Tuesday, March 23, 2004 3:29 PM
To: Java Programming on and around the iSeries / AS400
Subject: "Pointer or parameter error" calling Java method from RPG (JNI)
Hello,
Let me apologize ahead of time for the length of this email. I
am trying to provide as much detail as possible.
I am getting an error in my RPG program that calls a Java method
(JNI). I get a "Pointer or parameter error..."
When I investigate further I see a few more errors that cause
the message that are all something like this:
Message . . . . : Space offset X'00827000' or teraspace offset
X'0000000000000000' is outside current limit for object
QPADEV00R4WADEO
171174.
When I display the message details on that error it says that it is
happening way down in the JNI code somewhere:
>From program . . . . . . . . . : QJVAIPROP
From library . . . . . . . . : QSYS
From module . . . . . . . . : QJVAIPROP
From procedure . . . . . . . : Get_Prop_Info__FRPUsRUi
From statement . . . . . . . : 1673
To program . . . . . . . . . . : QJVAIPROP
To library . . . . . . . . . : QSYS
To module . . . . . . . . . : QJVAIPROP
To procedure . . . . . . . . : Get_Prop_Info__FRPUsRUi
To statement . . . . . . . . : 1673
The "Pointer or parameter error" happens in my RPG program on the first
eval that assigns a string object to my string object field. Here is the
code for the program:
H DftActGrp(*NO) ActGrp(*CALLER)
/Copy QSysInc/QRpgLeSrc,JNI
*-----------------------------------------------------------------------
-
* Declaration for Java object
*-----------------------------------------------------------------------
-
D j_Object S O CLASS(*JAVA:
D 'com.foo.bar.long.package.name.+
D ClassName')
*---------------------------------------------
* Returned field declaration for method
*---------------------------------------------
D j_ReturnVal S O CLASS(*JAVA:'java.lang.String')
*-----------------------------------------------
* Parameter field declarations for method
*-----------------------------------------------
D j_Parm1 S O CLASS(*JAVA : 'java.lang.String' )
D j_Parm2 S O CLASS(*JAVA : 'java.lang.String' )
D j_Parm3 S O CLASS(*JAVA : 'java.lang.String' )
D j_Parm4 S O CLASS(*JAVA : 'java.lang.String' )
*------------------------------------------------
* Prototype for constructor
*------------------------------------------------
D j_Constructor PR O EXTPROC(*JAVA :
D 'com.foo.bar.long.package.name.+
D ClassName' :
D *CONSTRUCTOR)
D CLASS(*JAVA :
D 'com.foo.bar.long.package.name.+
D ClassName')
*-----------------------------------------------------------------
* Prototype for Java method:
* restore in class jhaIFSFile in package com.jha.pinpoint.util
*-----------------------------------------------------------------
D j_Method PR O EXTPROC(*JAVA :
D 'com.foo.bar.long.package.name.+
D ClassName' :
D 'restore')
D CLASS(*JAVA : 'java.lang.String')
D parm1 O CLASS(*JAVA : 'java.lang.String' )
D parm2 O CLASS(*JAVA : 'java.lang.String' )
D parm3 O CLASS(*JAVA : 'java.lang.String' )
D parm4 O CLASS(*JAVA : 'java.lang.String' )
*-----------------------------------------------------------------------
*Procedure: newString
*Purpose: Create a Java String Object from a character field
*-----------------------------------------------------------------------
D newString PR O extproc(*JAVA:
D 'java.lang.String':
D *CONSTRUCTOR)
D Class(*JAVA:'java.lang.String')
D bytes 50A Const Varying
*-----------------------------------------------------------------------
*Procedure: getBytes
*Purpose: Get bytes from java string to place in char field
*-----------------------------------------------------------------------
D getBytes PR 7A EXTPROC(*JAVA:
D 'java.lang.String':
D 'getBytes') VARYING
*-----------------------------------------------------------------------
*
*-----------------------------------------------------------------------
**************
*Inline Code *
**************
C *entry plist
C parm value1 50
C parm value2 50
C parm value3 50
C parm value4 50
C parm r_status 7
C eval j_Parm1 = newString(value1)
C eval j_Parm2 = newString(value2)
C eval j_Parm3 = newString(value3)
C eval j_Parm4 = newString(value4)
*--------------------------------------------
* Instantiate object
*--------------------------------------------
C IF j_Object = *NULL
C EVAL j_Object = j_Constructor
C ENDIF
*--------------------------------
* Call Java method
*--------------------------------
C EVAL j_ReturnVal =
C j_Method(j_Object :
C j_Parm1 : j_Parm2 :
C j_Parm3 : j_Parm4)
C eval r_status = getBytes(j_ReturnVal)
C eval *inlr = *on
It happens on the first eval, right after the parameter list for the
program. I don't get it. I have been fighting this for a while now. I do
similar things in other programs, and I have another program that is
almost identical to this that works.
I CAN get this to work, if I go run another one (program that uses JNI
to call a java method) first. Some of the other programs were written by
a predecessor, and the main different between what I am doing and what
is in the other programs is that the contents of QSYSINC/QRPGLESRC,JNI
are copied directly into the program rather than using /COPY, and the
other programs call static main() methods that don't return anything. I
tried putting the contents of the JNI source member in my program, and
it didn't help (surprise). I wrote a version that started my JVM
manually (using the defaults as shown in the many examples on the web
and in the ILE RPG programming reference), and it would get passed the
evals, but then it would throw a NoClassDef exception even though my JAR
is defined in the system level CLASSPATH environment variable. I am at a
loss. This all looks kosher to me, but I guess I am over looking
something.
I can also get it to run, if I run in it in debug mode. If I run it in
debug right after it happens, it may or may not work. If I go in and
place my break point on that first eval and then hop around and inspect
the values that are passed in, and some of the object pointers, and then
step through, it will start working, and will work from then on as long
as I don't log out.
At first I thought the values weren't getting passed in, but that
doesn't seem to be the case. I can see that everything is passed in
correctly when I run it in debug.
I THINK This is all pointing to some sort of JVM problem, but I am not
sure where to look or what to do about it, or if that is indeed the
problem.
I apologize for the long winded e-mail, but this is really starting to
tick me off. I appreciate any help!
Dan Feather
dfeather@xxxxxxxxxxxxx
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