You need to download the OC4J from here
You move the downloaded file to the server where you want to configure. I installed it in the application server where i integrated the Apex with Oracle EBS. (Linux Box)
To integrate the Apex with Oracle EBS (11i/R12) please refer my blog entry http://balajiabhi.blogspot.com/search?q=apex
The server used: genius.chainsys.com
IP: 192.168.2.207
Ports used for Apex: 7778 (Application Server)
OC4J: 8888 (OC4J Instance created with the zip file downloaded)
1. Create a directory called oc4j (it is under /oracle/oc4j)
2. Move the downloaded file to the /oracle/OC4j and extract the content using unzip
3. Read the Readme.txt from the extracted file to start the oc4j
4. Prerequisite for the OC4j will be
Prerequisites
--------------
In order to use the OC4J zip distribution, a Java Platform StandardEdition (Java SE) Development Kit version 6.0, 5.0 (or 1.4.2) must be installed on the host machine.
in my case i chose /usr/java/j2sdk1.4.2_04
Instructions for configuring the OC4J instance:
1. Setup the JAVA_HOME and ORACLE_HOME as
export $ORACLE_HOME=/oracle/OC4j
export $JAVA_HOME=/usr/java/j2sdk1.4.2_04
2. Start the OC4J like (from the server screen itself, Donot use putty or anyother terminal to start oc4j, as it requires the studio to be deployed in the server)
./oc4j -start (from /oracle/OC4j/bin/)
During the startup it will ask you the password for oc4jadmin (In my case it is welcome) confirm the password and it will be initialized)
3. From the browser type http://hostname:8888/
should bring the oc4j webpage.
From the home, select
launch Appliction Server Control
the url will be like http://hostname:8888/em
provide the oc4jadmin password to enter into the ASCONTROL
4. Installing the FOP War:
Place the fop.war file (located in apex_install_directory/utlities/fop) in an accessible location on your local machine.
Navigate to your OC4J Oracle Enterprise Manager Console eg: http://localhost:8888/em/
Select the Applications Tab
Select Deploy Button
On the Deploy: Deployment Settings click the "Deploy" button
From the home > applications, you can see now, fop is up and running.
Now login to the apex using the url : http://genius:7778/pls/apex_r12/apex_admin
Select the Instance settings from manage services menu as below.
Oracle BI Publisher: Standard Support
Print Server Protocol: HTTP or HTTPS (depends on your configuration)
Print Server Host Address: the hostname for the machine where the java container is running - i gave the IP of the server
Print Server Script: /fop/apex_fop.jsp
Apply the changes and login to the Workspace and developer user. Locate the report to be taken in PDF format.
Apply the changes and click on the report you need to run.
You can see the name of the print label you passed earlier on the report to be taken as PDF. See the image below. Circled with red pen.