OC4J – The “Other” Oracle Application Server

How does
extensible markup language relate to the J2EE standalone version of Application
Server? If "extensible markup language" sounds unfamiliar to you, perhaps
you know it better by its acronym of XML. XML matters not to just to the J2EE
version of Application Server, but to all versions. The manner in which XML matters
is fairly significant: many configuration files are XML-based. If your DBA
responsibilities include administering J2EE applications based upon Application
Server, you face the learning hurdles of XML, Java and J2EE, how Oracle
interfaces with Java (OC4J, more on that later), and Application Server itself.
Chances are you have seen XML in action and may not have even noticed it.
Oracle 10g’s staging information uses a file named products.xml instead of
products.jar.

If coming
from a Forms and Reports Services standalone background, the J2EE version will be
somewhat familiar, but even within this "known" territory, there are
many differences. For example, using true or false: all versions of Application
Server are installed using Oracle Universal Installer, so all you ever need to
look for in the "Disk 1" directory is the setup.exe (or runInstaller)
executable? As we will see later on, the answer is false.

This
article is the first of a multi-part series focusing on Oracle’s more Web-like
version of Application Server, J2EE applications, and XML. Being able to
differentiate the versions of Application Server (what is common, what is
different), basic administration (using XML configuration files), performing a
new type of installation, and acquiring an XML editing tool (free and lasts
forever) are some of the topics that will be covered.

The different flavors of Application Server

Which
version do you need, is it part of a bundle, and does it come in a standalone
version? Part of the answer is shown in the version comparison matrix found
under the Middleware (not Applications) link under "Products" at www.oracle.com (see http://www.oracle.com/appserver/appserver_family.html).

Scrolling
down a bit on the page, the OC4J version shows the following availability by version.

Oracle Application Server Containers for J2EE (OC4J)

Version Availability

Java

SE/SE1

EE

Standalone

Fastest J2EE-certified Java environment with support for
Web services (UDDI, SOAP and WSDL), Fast Start Fault Recovery Architecture,
cluster support for JSPs, servlets, and EJBs, and J2EE-based security
framework.

Yes

Yes

Yes

NA

Under
product information for Application Server at OTN, you can expand a list of
features for each version. The two tables below show a consolidated listing for
each type. Common elements are aligned at the top.

Application Server 10g
Release 2

J2EE and Web Cache

Oracle HTTP Server Oracle Application Server Containers
for J2EE (OC4J)

Oracle Application Server Web Cache

Oracle Enterprise Manager 10g Application Server Control

OracleAS Backup and Recovery Tool

Oracle
Application Server Portal

Oracle
Application Server Wireless

Oracle
Sensor Edge Server

Oracle
Database Server 10g (10.1.0.4.2)

Oracle
Internet Directory

Oracle
Application Server Single Sign-On

Oracle
Application Server Directory Integration Provisioning

Oracle
Application Server Delegated Administration Services

Oracle
Application Server Certificate Authority

Oracle
Application Server Forms Services

Oracle
Application Server Reports Services

Oracle
Application Server Personalization

Oracle
Business Intelligence Discoverer

Oracle
Security Developer Tools

Oracle
Application Server Guard

Oracle Application Server Containers for J2EE

Oracle HTTP Server Oracle Web Cache

Oracle Enterprise Manager 10g Application Server Control

OracleAS Backup and Recovery Tool

OracleAS
Upgrade Assistant and Upgrade Plug-Ins

OracleAS
Change IP/Host Name Tool

OracleAS
Cloning Scripts

Oracle
XML Developer’s Kit

 

Oracle
Application Server 10g Release 2 (10.1.2.0.1) Standard Edition One

Oracle
Application Server J2EE Downloads

As
another example, the Standalone User’s Guide should be available at http://localhost:8888/standaloneguide.pdf.
This URL suggests that where the PDF is located is also the Web server document
root. The root (for me) is C:\oracle\oc4j\j2ee\home\default-web-app, and a
simple test of trying to access other files within the default-web-app
directory should prove this to be true.

Where is
Enterprise Manager for this version of Application Server? Despite Oracle’s Web
site saying this version includes Enterprise Manager, it does not. The next
version up – J2EE and Web Cache – is the minimum version type to get Enterprise
Manager.

Just for
grins, if you note that the contents of the server.xml file remind you of a
simple HTML file, try opening this (or any) XML file in a browser.

In Closing

So far, we
have seen a listing of the features included in the four types of installation
for Application Server. Applications can be deployed via the standalone OC4J
version, and administration can be performed via the direct editing of (many)
XML files. Knowing the specifics of XML is not necessary, but it certainly
helps to have an appreciation of the who-what-where of what Enterprise Manager
changes when you, as the administrator, are making changes via the EM console.

»


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Steve Callan

Steve Callan
Steve Callan
Steve is an Oracle DBA (OCP 8i and 9i)/developer working in Denver. His Oracle experience also includes Forms and Reports, Oracle9iAS and Oracle9iDS.

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