Cross platform operating system calls from Java

Question

For our application we need to call an external program to perform FTP. We use ncftp as it's available on all the server platforms our clients use (Sun, HP, Linux, Windows). Up to now we've been using a Java program that listens to the Oracle pipe and sends a string to the OS.
Now we are using 8i we thought it would be better to use Java within Oracle as this should reduce problems due to the external program not running. On Windows it works fine, but on Linux runtime.exec does not seem to take account of the system path. If I send something like '/usr/bin/ncftpput ...' it works, but I can't rely on the executable being in that directory although it should be somewhere in the path. I want to just pass 'ncftpput ...'.
Ideally I want to be able to make the code OS independent, but would consider doing something in the Java part to detect the OS and adapt accordingly, perhaps by using a shell e.g. '/bin/sh -c ncftpput ...', but I've had problems with that using the whole command line and can I rely on having a specific shell on all *nix systems?
At some point we'd like to do all the FTP from within Oracle, but that looks like a bigger project.
Any ideas/suggestions?
Thanks
Steve

Answer 1

Steve,
To determine the OS, you should be able to check the System properties. As an example, when I run this (quick and dirty) sample code, I can see that os.name=Windows NT on my Windows instance:
CREATE OR REPLACE JAVA SOURCE NAMED "envTest" AS public class envTest {
public static void getEnvVar() {
System.getProperties().list(System.out);
CREATE OR REPLACE PACKAGE envTest IS
     PROCEDURE getEnvVar;
END;
CREATE OR REPLACE PACKAGE BODY envTest IS
     PROCEDURE getEnvVar IS
     LANGUAGE JAVA NAME 'envTest.getEnvVar()';
END;
To see the output after executing envTest.getEnvVar, map System.out to DBMS_OUTPUT before running it, as follows:
set serveroutput on
begin
dbms_java.set_output(100000);
end;
Hope this helps,
-Dan
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