Ok,
I was far away.
First I had to manually install Javam in oracle, because I hadn't done it at Oracle installation (2 years ago). And so I found out what javasys... role was.
Then I had to download from technet.oracle the xmlparser2.jar and load it using loadjava.
And now, I just found out that loadjava is a shell script setting a BIG classpath and calling jre, which none of it is in my chroot jail.
I'm now trying to decide wether to duplicate the java environment in the jail or running the server outside the jail for installation.
I let you know if I succeed.
bye
