Non-J2EE Components

In addition to the basic J2EE services, the full Oracle 10g AS Enterprise Edition offers a number of non-J2EE components that support the product as a whole.

It's critical to understand that 10g AS is more than just a renamed Orion J2EE server. 10g AS is a tightly integrated web application server built on the Apache web server (modified and renamed OHS), using the Orion J2EE application server (modified by Oracle and renamed OC4J), a Lightweight Directory Access Protocol (LDAP), which is renamed Oracle OID, as well as advanced features, include Oracle Web Cache and Oracle Clustering, for those sites requiring maximum performance and reliability. These components are described in great detail in Chapters 1521 and on Oracle websites ( http://otn.oracle.com ), so we'll only take a brief look at each here.

10g AS also includes a mix of longtime Oracle products such as Oracle Portal, Forms, Reports , Discover, and the PL/SQL Web Toolkit, as well as useful Java development tools such as TopLink and JDeveloper. We'll briefly cover these here, in order to give you a complete overview of what Oracle 10g AS can provide, but we don't cover them in any detail in this book.

Oracle HTTP Server

All commercial editions of Oracle 10g AS include OHSan extended version of the popular Apache web server. This server relies on proven Apache code to handle all incoming HTTP and HTTPS requests, dispatching them appropriately to OC4J or other resources through the standard Apache "mod" architecture. (The OC4J Standalone development edition handles HTTP requests directly from the web container.)

OHS adds the following enhancements to the underlying Apache server:

Integration with OC4J. Requests for web application resources are passed through the OC4J web container, and session-aware load balancing and failover are supported across multiple OC4J instances.
Integration with Oracle 10g AS Single Sign-On. Allows the web server to authenticate users through SSO and passes the credentials through to web applications.
High availability and load-balancing optimizations. Requests can be distributed among a cluster of web servers and application servers, while respecting user sessions. Servers that fail are automatically detected and restarted.

Note	To accommodate companies who already have investments in Netscape's NES or Microsoft's IIS, this functionality is also made available as plug-ins for those web servers.

Web Cache

Oracle 10g AS Web Cache sits in front of web and application servers and serves up cached content in response to HTTP/S requests, and only hits those servers for new or expired content. This caching layer can dramatically improve the performance of certain types of web applications.

Until recently, it was very difficult for dynamic applications to take advantage of web caching. When just about every page includes a personalized greeting or account detail, traditional caching proxies won't do. Oracle has solved this problem by implementing the Edge Side Includes (ESI) standard. In particular, the Java version of this standard (JESI), allows JSP developers to easily mark certain parts of a page as dynamic and permit the rest to be cached. When a request comes in, the dynamic parts are executed and the full page is reassembled at the Web Cache layer.

Oracle 10g AS Web Cache also supports the following:

Rules-based and programmatic invalidation of cached content
Delivery of specific cached content based on user characteristics
Clustering of cache servers
Load balancing and throttling
Form-based or client certificate authentication (but not basic authentication)
Hierarchical caching (across diverse geographical locations)

The configuration of Oracle 10g AS Web Cache will be covered in Chapter 19.

For applications that need to perform significant post-processing on cached data, Oracle 10g AS also includes a Java Object Cache and Web Object Cache, which can be directly manipulated through published APIs. Documentation is available for each on the Oracle Technology Network (OTN) website.

Application Server Control

The web-based Oracle Enterprise Manager (OEM) for 10g AS has been renamed Application Server Control (ASC). This product is a web-based administrative console for the Oracle 10g AS platform that allows you to manage and monitor all of the components included in your installation. In particular, this tool is often used to configure new OC4J instances, deploy J2EE applications to them, and monitor performance. It's similar to the management consoles provided for WebLogic and WebSphere.

Alternatively, you can use command-line tools to perform or automate many of the same administrative tasks .

Note	OC4J Standalone instances cannot be managed through the OEM website, but rather only through manual updates to a collection of XML configuration files (see Chapter 4). These same files should not be directly edited in a commercial edition.

The configuration of applications and server processes through ASC ( formally Enterprise Manager) will be covered in Chapters 16 and 17.

Single Sign-On

The term S ingle Sign-On or SSO refers to the idea that users should only authenticate once to access most of the applications they use on a daily basis. This reduces the number of passwords each user must remember, and the number of systems that need to be updated whenever privileges change, thus improving both security and productivity.

Oracle 10g AS Standard and Enterprise Editions provide SSO functionality for web-based applications. SSO is unavailable for nonweb applications. The first time a user tries to access a protected application, the OHS will redirect her to the SSO server, which will check her credentials against an OID repository. If the logon is successful, she is given an encrypted cookie, which will automatically authenticate her to any application protected by Oracle 10g AS SSO. Similarly, when she signs off, the SSO server can ensure that all her application sessions are terminated .

Applications deployed within Oracle 10g AS can easily take advantage of SSO. However, it's often necessary to authenticate to external legacy or partner applications, some of which need to continue maintaining their own usernames and passwords. Fortunately, the SSO server can also store these additional credentials for each user and pass them on to the external system at the appropriate time.

If additional features are needed (such as authenticating via a SecureID access card), you can also integrate third-party security frameworks like RSA ClearTrust, which provide a greater range of authentication types.

Content Management SDK

The Oracle Content Management SDK is a database- backed file system that supports indexing, versioning, fine-grained access control, notification, and other content management features. Users can interact directly with the repository through a variety of out-of-the-box clients. At the same time, developers can work with a Java API to build custom parsers, renderers, user interfaces, clients , and more.

Under the covers, all documents are stored as LOBs in an Oracle database and can be configured to work with most Oracle text options. Out-of-the-box clients are provided for FTP, SMB, WebDAV, IMAP4, AFP, and NFS.

Documentation for the Oracle Content Management SDK is available on the OTN website (see http://otn.oracle.com/documentation/cm_sdk.html ).

Integration

Oracle 10g AS Integration provides an infrastructure for integration between enterprise applications both inside and outside the corporate firewall. Like other J2EE-based Integration servers, it provides a number of out-of-the-box J2EE Connectors for communication with common systems (such as SAP and PeopleSoft). It also supports web services interfaces and provides a complete workflow system to control how data is routed, transformed, and processed once it's received.

More information about Oracle 10g AS Integration is available on the OTN website (see http://download-east.oracle.com/docs/cd/B10464_01/integrate.htm ).

Oracle Internet Directory

OID is an LDAP directory built on top of the Oracle database. It's used to store user identity, authentication, and authorization information for enterprise applications. It can be used as the sole user repository, or linked to other directories, like iPlanet, throughout the enterprise. The latter option is useful when integrating with existing systems (such as human resources) or when a corporation has already standardized on a different directory server.

Oracle 10g AS SSO relies on OID to coordinate authentication across multiple applications (see Chapter 20).

JDeveloper

JDeveloper is an integrated development environment (IDE) for Java that's designed to accelerate Java and J2EE application development for the Oracle 10g AS platform. Like BEA's WebLogic Workshop and IBM's WebSphere Application Developer, JDeveloper provides wizards to automatically generate many of the standard and server-specific deployment descriptors. It also incorporates a variety of timesaving features, including the following:

Design wizards for J2EE 1.3 components
Embedded OC4J server
Web service development wizards
UML class and activity diagrams with round-trip code generation
Swing and Abstract Window Toolkit (AWT) user-interface designer
JSP viewer
Support for the Struts web application framework
Integration with Ant, JUnit, CVS and other popular development tools
Advanced debugger and profiler

Though it's missing some of the cutting-edge advances and portability found in independent IDEs like Eclipse and IntelliJ/IDEA, it offers more complete modeling, user-interface design, and OC4J server integration. This can be ideal for development teams committed to Oracle 10g AS.

All three commercial Oracle 10g AS editions include five or more JDeveloper licenses.

TopLink

TopLink is an object-relational mapping tool that's designed to quickly and easily persist Java objects to a relational database like Oracle. Unlike EJB container-managed persistence, it allows developers to map arbitrary relationships and to persist any plain old Java objects (POJO), not just entity beans. It can also help to reduce dependencies between Java code and the underlying data schema.

The features include the following:

Graphical workbench for mapping objects to database tables
Support for complex relationships, including subselects
Flexible query capabilities, allowing SQL, EJB-QL, and Java object-based expressions
Support for multiple application servers, databases, and architectures
Caching options to improve performance

Overall, TopLink is a useful tool that offers flexible, high-performance object relational mapping (ORM) capabilities.

A point of interest with TopLink is that the EJB 3.0 specification looks set to use a POJO-based ORM model for persistence. This has been brought about mainly by the success of the open -source Hibernate project ( www.hibernate.org ), a project that is very similar to TopLink.

TopLink is included with every commercial edition of Oracle 10g AS and can also be downloaded through the OTN website.

Portal

Oracle 10g AS Portal provides a framework for the creation of enterprise portals that provide corporate users a single destination for all of their daily business. Individual portlets can be designed to allow access to just about any enterprise application or web service, and can be arranged in custom pages that maximize each user's productivity.

Of course, it's important to understand the difference between a portal framework and the components built upon it. Out of the box, Oracle 10g AS Portal provides everything you need to build and manage a basic enterprise portal with dozens of portlets for document management, collaboration, syndication, and reporting. From this point, you can choose to integrate your own portlets and applications, purchase prebuilt components from Oracle, or in many cases, do a little of both.

In general, portlets developed for one portal server aren't compatible with others. However, the Java Community Process (JCP) has recently finalized a common Portlet API (Java Specification Request 168), which will hopefully lead to increased portability in the future.

More information about Oracle10g AS Portal is available on the OTN website (see http://download-east.oracle.com/docs/cd/B10464_01/portal.htm ).

Discoverer

Discoverer is a user-friendly tool that lets end users build ad hoc queries and reports against corporate databases and data warehouses. More information is available on the OTN website (see http://otn.oracle.com/documentation/discoverer.html ).

Reports

Oracle 10g AS Reports is a more sophisticated report writer (aimed at developers, not end users) that supports both web-based and printable reports in a variety of formats. More information is available on the OTN website (see http://otn.oracle.com/documentation/reports.html) .

Forms

Oracle Forms is a Rapid Application Development (RAD) environment that lets developers create useful database-centric applications for minor business needs. Though it isn't ideal for complex enterprise applications, it can be appropriate for low-traffic, timesaving tools. The latest release includes web delivery through a Java API and may be integrated with SSO and other Oracle 10g AS services.

More information about Oracle Forms is available on the OTN website (see http://otn.oracle.com/documentation/9i_forms.html ).

Personalization

Oracle 10g AS Personalization analyzes the behavior of anonymous and logged-in users and adjusts content based on a tunable recommendation engine. It's most useful for e-commerce and portal applications.

More information about Oracle 10g AS Personalization is available on the OTN website (see http://otn.oracle.com/products/personalization/index.html ).

Wireless

Oracle 10g AS Wireless supports the development and deployment of browser-based applications, voice-based applications, messaging, and J2ME applications for wireless devices. Along with an enterprise-class wireless gateway, it also includes a developer toolkit that integrates especially well with Oracle's JDeveloper IDE, allowing developers to quickly develop applications for the most common wireless platforms.

More information about Oracle 10g AS Wireless is available on the OTN website (see http://otn.oracle.com/products/iaswe/index.html ).