344 Building Java Applications for the iSeries Server with VisualAge for Java 3.5
One important fact should be noted here. If the program on the iSeries server issues a
message that waits for a response (an inquiry message), then
control is never returned. The
submitOrder() method hangs on the ordEntrPgm.run() method. If this occurs, you must
check the server job that is handling the request on the host iSeries server. This job has a
name of QZRCSRVS, and its job log should be viewed. If the program runs successfully, the
submitOrder() method updates the status text field accordingly.
This concludes the application flow from the Java client perspective. Now, we examine the
code changes made in the RPG code to accommodate the Java client.
8.5 Changes to the host Order Entry application
This section contains details about the transition of the RPG code on the host. The changes
are made, so the application can run in one of two modes:
򐂰 As a native application with a 5250 screen interaction
򐂰 In conjunction with the newly created Java client
For the most part, the changes are examined in the same sequence as the client application
flow.
8.5.1 Providing a customer list
We saw earlier that one of the first things the client does after connecting is to request a
customer list. This was done by executing an SQL stored procedure using JDBC. The stored
procedure is actually an RPG program called SLTCUSTR. To accommodate the Java client,
two subroutines are added to the program and the logic flow is changed when a second
parameter is detected. In the original version of SLTCUSTR, the logic flow can be
summarized as:
򐂰 Run the OpenCust subroutine (declares and opens the cursor for CSTMR file).
򐂰 Run the BldSfl subroutine (populates and displays the subfile).
򐂰 Run the Process subroutine (detects the chosen customer and displays).
The new logic flow can be summarized as:
򐂰 Run the CloseCust subroutine (resets the cursor for multiple client requests).
򐂰 Run the OpenCust subroutine (same behavior as the original version).
򐂰 If more than one parm, run the ResultSet subroutine (makes result set available to the
caller of the stored procedure).
򐂰 If only one parm, continue as the original version did. Run the BldSfl subroutine, and then
run Process.
The added subroutines are minimal code changes. Here is the CloseCust subroutine:
CSR CloseCust BEGSR
* ----------
C/Exec Sql Close CUSTOMER
C/End-Exec
*
CSR ENDSR
As previously mentioned, this ensures that the cursor is at the beginning of the file when
multiple requests are received from the client. Now, we examine the ResultSet subroutine:

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