Calling AS/400-native programs from Java: I'm crawling out from under a proverbial rock

In the past, when I've had to call AS/400-native programs from Java
programs on the AS/400, I've done it with a "Runtime.getRuntime().exec()"
call, building the input parameters into what I passed to "exec()," doing
a "getInputStream()" on the returned "Process," and having the
AS/400-native program write its output to STDOUT, where it would be
readable to the calling Java program.

At the time, I don't think Toolbox calls were an option, and even once
they were, the above seemed a more straightforward way of making the call
than anything I could find in the Toolbox.

Is there a quick, easy way for Java (on the AS/400) to call an
AS/400-native program (on the same box) and get a single character string
return value, of which I'm not yet aware?

--
JHHL