Example of a COBOL COMMIT wrapper

Figure 1 is a simple example of a COBOL COMMIT wrapper that, while compiled with the DLL option required for Java™, can be statically linked with a main non-DLL application module. In this example, a procedural COBOL program invokes a Java method. Only the non-DLL module objects that need to call the new COMMIT function need to be recompiled. You can also perform a similar function for ROLLBACK.

Figure 1. Example: COBOL COMMIT wrapper

*----------------------------------------------------------------
*                                                                
* Program Name   : COBCOMIT                                      
* Objective      : Call RSS global commit via batch container    
*                                                                
*----------------------------------------------------------------
 IDENTIFICATION DIVISION.                                        
 PROGRAM-ID. "COBCOMIT" IS RECURSIVE.                            
                                                                 
/                                                                
 ENVIRONMENT DIVISION.                                           
*--------------------                                            
 CONFIGURATION SECTION.                                          
 REPOSITORY.                                                     
     Class JavaException is "java.lang.Exception"                
     Class UserControlledTransaction is                          
           "com.ibm.batch.spi.UserControlledTransactionHelper".   
 INPUT-OUTPUT SECTION.                                            
 FILE-CONTROL.                                                    
                                                                 
 DATA DIVISION.                                                   
 FILE SECTION.                                                    
                                                                  
 WORKING-STORAGE SECTION.                                         
 01 ex object reference JavaException.                            
                                                                  
 LINKAGE SECTION.                                                 
 01 RETCODE PIC S9(9) USAGE IS BINARY.                            
 COPY JNI.                                                        
                                                                  
 PROCEDURE DIVISION RETURNING RETCODE.                            
*---------------------------------------------------------------- 
*                                                                 
*    Test batch cobol commit.                                     
*                                                                 
*---------------------------------------------------------------- 
 PROGRAM-BEGIN.                                                   
     SET ADDRESS OF JNIENV TO JNIENVPTR                           
     SET ADDRESS OF JNINATIVEINTERFACE TO JNIENV                  
     Display "Calling into Java commit"                           
     Invoke UserControlledTransaction "commit"                    
     Display "Returned from Java commit"                          
     Perform ErrorCheck                                           
     Goback                                                       
     .                                                            
 PROGRAM-END.                                                     
     GOBACK.                                                      
* need to perform exception check / stack trace at this point ?   
                                                                  
ErrorCheck.                                                      
    Compute RETCODE = 0                                          
    Call ExceptionOccurred                                       
         using by value JNIEnvPtr                                
         returning ex                                            
    If ex not = null then                                        
         Call ExceptionClear using by value JNIEnvPtr            
         Display "Caught an unexpected exception"                
         Invoke ex "printStackTrace"                             
         Compute RETCODE = 99                                    
    End-if                                                       
     .                                                           
  End program "COBCOMIT".

Figure 2 shows an example of the JCL that would be needed to compile the COMMIT wrapper shown in Figure 1.

Figure 2. Example: JCL used to compile COMMIT wrapper

//COMPCMIT JOB ,'STEVE PROGRAM ',
//             NOTIFY=&SYSUID,
//             MSGCLASS=X,   
//             CLASS=A,
//             REGION=0M,
//             TIME=120
//COMPILE  EXEC IGYWC,LNGPRFX='SYSPROG.MNT.COBOL42',
//         COND=(4,LT),
//         PARM.COBOL=(NOSEQUENCE,RENT,LIB,THREAD,
//         NODYNAM,DLL)
//COBOL.SYSLIB DD DSN=SUIMGJB.PRIVATE.JNI.COPY,
//             DISP=SHR
//COBOL.SYSIN  DD DSN=SUIMGJB.PRIVATE.DOCXMP.COBOL(COBCOMIT),
//             DISP=SHR
//COBOL.SYSLIN DD DSN=SUIMGJB.PRIVATE.COBOL.OBJ(COBCOMIT),
//             DISP=SHR
//