Re: Java to RPG

Peter Connell wrote:

I can't execute a method in a java class and have it call back to a
procedure back in my rpgle program.

You can sort of do that; the Java class would call a native method which can then call through to your procedure.

Your Java looks like this:

class MYCLASS
...
static
{
System.loadLibrary("MYSRVPGM");
or
System.load("/QSYS.LIB/MYLIB.LIB/MYSRVPGM.SRVPGM");
}

native static int myNativeMethod(int i);

...
x = myNativeMethod(y);

Your RPG module for srvpgm MYSRVPGM looks like this:

D myNativeMethod pr 10i 0 extproc(*java:'MYCLASS'
D :'myNativeMethod')
D i 10i 0 value

P myNativeMethod b export
D myNativeMethod pi 10i 0
D i 10i 0 value
/free
return myRealProcedure(i);
/end-free
P myNativeMethod e

You can call the native method from RPG too, using the same prototype, but it would be a Java call, going through JNI to Java and back to the native code.