-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Ray,
On 9/25/12 8:46 PM, Ray Collins wrote: > I am using Tomcat7.0. The web application I created executes a > script from the command line using Runtime.getRuntime(). This > script sends an http: request to another server that is on the > local network. For Some reason the script executes as if it has > sent the http request but it really has not. Its like Tomcat is > operating in a sandbox when it comes to accessing this URL on my > local network. I am using Ubuntu Server 12.04 . If i run the > script manually from the command line the script can access the URL > with no problem. Why cant the script that tomcat has executed > access this resource. Any help is greatly appreciated. Using Runtime.exec is fraught with difficulty, and most people don't do it right. Remember that you basically need 3 threads in order to run Runtime.exec: one to pump-in data for the sub-process's stdin (or you can close stdin for the sub-process and save yourself a thread), one to drain stdout and one to drain stderr. Sadly, there are no non-blocking options for draining stdout and stderr that I know of -- though I suppose you could go into a busy-wait checking stdout.available() and stderr.available() and draining them several bytes at a time. If you don't drain stdout and stderr, your process will block and if you are waiting on that Process from a request-dispatch thread, your thread will stall forever. Make sure you are properly using Runtime.exec or use a library that wraps it for you and handles all this complexity for you. Note that if you expose this capability publicly, you will essentially allow any remote user to execute an arbitrary number of processes on your server: you might want to consider using a queue with a fixed-width "exec pipeline" so that you don't launch 5000 processes on your app server. Also be very careful with command-line-building. If you are calling a shell to parse some stuff and then execute, be very aware of CLI injection attacks, too. - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.17 (Darwin) Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Mozilla - http://www.enigmail.net/ iEYEARECAAYFAlBjJHMACgkQ9CaO5/Lv0PA9KACgopecKKlBuTK/kVqZjfvoP7BF 5r4AoIgvdJjXjQbUOuIV06BVDaAO1dSl =2YIW -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
