On 21-Feb-2014 16:59 -0800, James H. H. Lampert wrote:
Here's the scenario:
I'm calling Scott Klement's JDBCR4 service program (actually, my own
expanded version thereof, but...). I try to connect to a system that
rejects the connection. A procedure in the service program puts a
diagnostic message in the joblog, a CPF9897 with the text (at least
in the version of the scenario I can readily reproduce) "The
application server rejected the connection. (General security
error.)"
I want to be able to retrieve and display this diagnostic from the
program (ILE RPG, FWIW, but this is presumably a system API
question, not an RPG question) that called JDBCR4.
If F9 the message, I get (and JDBCR4QV is my expanded JDBCR4):
From program . . . . . . . . . : JDBCR4QV
From library . . . . . . . . : AQUESTVIEW
From module . . . . . . . . : JDBCR4
From procedure . . . . . . . : JNI_CHECKERROR
From statement . . . . . . . : 7209
To program . . . . . . . . . . : JDBCR4QV
To library . . . . . . . . . : AQUESTVIEW
To module . . . . . . . . . : JDBCR4
To procedure . . . . . . . . : JNI_CHECKERROR
To statement . . . . . . . . : 7209
I can see the message by doing a DSPJOBLOG, but I can't figure out
how to make the calling program see it. Can I do so without further
modifications to my expanded JDBCR4?
If an application intends that the invoking program should be able to
access the message, the application either should be sending [e.g.
Resend Escape Message (QMHRSNEM) API or Send Program Message (QMHSNDPM)
API or CL command (SNDPGMMSG)] directly to the invoker or moving the
messages up-the-stack [Move Program Messages (QMHMOVPM) API]. When the
application instead sends the messages only to the invoked procedure or
program or only to the procedures within [i.e. to\within itself], then
the access to those message from the invoker is difficult. There is a
procedure documented to receive the messages; I could not easily locate
a link. That method involves obtaining a message mark prior to the
invocation of the application that does not /play well with others/, and
then repeatedly invoke the Receive Program Message (QMHRCVPM) API or the
CL command (RCVMSG) with a decremented message key value while also
monitoring and handling [best to include the removal of] the conditions
of "message key not found"; being a stand-alone procedure the procedure
could globally monitor\ignore that exception, and then remove all
messages in its queue upon completion, rather than RCVMSG RMV(*YES)
after each instance of that exception.
If I had access to the source of the application that sends the
messages, I would prefer to /correct/ that application to move the
messages up to the invoker.
Hmmm... I had already found the link, in essence; i.e. the link was
found at the bottom of the topic _Call message queue_ with the parent
topic _Job message queues_ that I found by searching InfoCenter on the
tokens:
receiving messages stack
<
http://pic.dhe.ibm.com/infocenter/iseries/v7r1m0/topic/rbam6/msgcallqueue.htm>
IBM i 7.1 Information Center -> Programming -> Control language ->
Messages -> Message queues -> Job message queues
_Call message queue_
"A call message queue is used to send messages between one program or
procedure and another program or procedure.
As long as a program or procedure is on the call stack (has not returned
yet), its call message queue is active and messages can be sent to that
program or procedure. After the program or procedure returns, messages
can no longer be sent to it. Message types which can be sent to a call
message queue include informational, request, completion, diagnostic,
status, escape, and notify.
...
Note: When you are using the command entry display, you can display all
the messages sent to the job message queue by pressing F10 (Include
detailed messages). After the messages are displayed, you can roll
through them using one of the roll keys.
You can also display the messages for a job by using the Display Job Log
(DSPJOBLOG) command.
Parent topic: _Job message queues_
Related tasks:
_Receiving a message from a program or procedure that has ended_
"
<
http://pic.dhe.ibm.com/infocenter/iseries/v7r1m0/topic/rbam6/rcvmsgpgm.htm>
IBM i 7.1 Information Center -> Programming -> Control language -> Messages
_Receiving a message from a program or procedure that has ended_
"Occasionally, there is a need to receive messages from the job log that
are sent to a call message queue that is no longer active.
For example, PGMA calls PGMB and PGMB sends a diagnostic message to
itself and an escape message to PGMA. PGMA can easily receive the escape
message that was sent to it, but sometimes it is necessary to also
receive the diagnostic message. Because the diagnostic is on a call
message queue that is no longer active, the message must be received by
using a message reference key. This can be done, but it takes more work
than one simple receive message command.
..."
midrange.com
