Example of JVM COBOL Interoperation with Native Code

The following pair of programs show group items being used to interoperate between JVM COBOL and native COBOL.

Native COBOL:

    program-id. NativeProgram as "NativeProgram".
    linkage section.
    01 pets.
       03 p1 pic xxx.
       03 p2 pic xxx.
       03 result pic x(6).
    procedure division.
       goback.
       entry "SwapStrings" using pets.
          display "p1='" p1 "' p2='" p2 "'"
          move p1 to result(4:3)
          move p2 to result(1:3)
          goback.
    end program NativeProgram.  

JVM COBOL:

    program-id. JVMProgram as "JVMProgram".
    01 pets.
        03 dog pic xxx value "dog".
        03 cat pic xxx value "cat".
        03 result pic x(6).
    01 nat-ptr procedure-pointer.
    procedure division.
       set nat-ptr to entry “NativeProgram"
        display ""           
        display "Calling native program"
        display "======================="
        display "Pass in 2 strings: '" dog "' & '" cat "'"
        perform reset-all
       call "SwapStrings" using pets
        display "Native program swaps strings"
        display "result = '" result "'"
        display "" 
        goback.
    reset-all section.
        move spaces to result
        .   
    end program.