Calling a remote IMS™ transaction from EGL-generated Java™ code or the debugger

The coding task is to define an input and output record and to write a call statement that includes those records. The input record must match the message that the IMS™ transaction expects to retrieve from the IMS™ message queue, and the output record must match the message that the IMS™ transaction inserts to the message queue. For example, the following code invokes transaction TXN1 and provides both the IMS™ header information and the data:

   inRec InputRecord;
   outRec OutputRecord;

   inRec.TRANSCODE = "TXN1";
   call "TXN1"(inRec, outRec);

   record InputRecord type BasicRecord
      10 LL smallInt;         // IMS LL field
      10 ZZ smallInt;         // IMS ZZ field
      10 TRANSCODE char(8);   // IMS transaction code
      10 data;                // user data
         15 f1 char(10);
         15 f2 char(20);
   end

   record OutputRecord type BasicRecord
      10 LL smallInt;         // IMS LL field
      10 ZZ smallInt;         // IMS ZZ field
      10 data;                // user data
         15 f2 char(20);
         15 f3 char(20);
         15 f4 char(20);
   end

In a second example, the IMS™ transaction TXN2 expects input in the form of an MFS map and responds to the caller with an MFS map. Here are the record parts:

   record InputRecord type BasicRecord
      10 LL smallInt;                   // IMS LL field
      10 ZZ smallInt;                   // IMS ZZ field
      10 MID-TRANSCODE char(8);         // IMS transaction code
      10 ...                            // Other MFS MOD header data
      10 data;                          // user data
         15 field1Attribute char(8);
         15 field1Data... 
   end

   record OutputRecord type BasicRecord
      10 LL smallInt;                   // IMS LL field
      10 ZZ smallInt;                   // IMS ZZ field
      10 ...                            // other MFS MOD header data
      10 data;                          // user data
         15 field1Attribute char(8);    // account for MFS attribute bytes
         15 field1Data...
   end

The linkage build descriptor option must reference a linkage options part that includes a callLink element for the called transaction. Do as follows when you work on the callLink element:

• Set type set to REMOTECALL
• Set remotePgmType set to STATELESS
• Set remoteComType set to IMSTCP or IMSJ2C
• Set conversionTable, location, and serverID as appropriate for the remoteComType setting, as described in the reference topics for those attributes

At run time, the process is as follows:

1. EGL-generated Java™ code creates an IMS™ interaction and calls the execute method on that interaction, passing the input and output records
2. IMS™ Connect provides the input data to the IMS™ message queue, and the IMS™ transaction retrieves it by issuing a GU call to the I/O PCB
3. After processing the input data, the IMS™ transaction inserts output data to the message queue by issuing an ISRT call to the I/O PCB
4. IMS™ Connect returns the output data to the execute method, which returns the data to the caller