WEB AS ABAP +JAVA for XI on Linux

I installed central instance and database instance successfully, I have to add Java Stack for XI to work. When I am trying Java Add-In through sapinst gui as the sap and db were up and running. From the install first page of sapinst gui, i selected Java Add-In for ABAP> Oracle>Central System> Java System Finalization and clicked next, the installation hung. I tried restarting the server, left untouched for more than 6 hours.. nothing happening. I tried 3 to 4 times ..same result

Can somebody give a idea what may be happening.

I have Linux OS with Java 1.4.2_06 already installed.

thanks