Java / Tomcat没有足够的权限来执行'java'

Question

I have the following code running in one of my Java-Servlets on my Tomcat server on Ubuntu:

ProcessBuilder pb = new ProcessBuilder( "java", "-jar", "test.jar", Integer.toString( jobId ), Integer.toString( software ), Integer.toString( entryPoint ), application );
pb.directory( new File( "/home/user/Folder" ) );
proc = pb.start();

But in line three I get this error:

java.io.IOException: Cannot run program "java" (in directory "/home/user/Folder"): error=13, Keine Berechtigung

It is german and means, that it doesn't have enough rights to execute 'java'.

Does anyone know how to fix that?

Answer 1

this means that the user who starts the tomcat server does not have permissions to launch java process inside /home/user/Folder.

check who's running tomcat with:

ps aux | grep tomcat

either change the owner of /home/user/Folder so that it's owned by the user who runs the tomcat or adjust the file permissions accordingly

to change the owner of the directory you execute the following:

chown -R tomcat /home/user/Folder

to add permissions (so that tomcat can access the folder) you execute the following:

chmod -R o+rwx /home/user/Folder

Note! you only need to choose one method, not both.

Answer 2

Possible cause: AFAIR from your other question, you use a Linux machine, so there can be (besides the standard Unix security) also SELinux in action, which allows to specify further restrictions. And it is quite possible, that there is a restriction imposed on tomcat (or even java itself), that prevents it from starting other processes (either all, or from a specified list).