EJB server articles and products

EJB servers (application servers) are component-based software that resides in the middle-tier of a server centric architecture. They provide middleware services for security, state maintenance, along with data access and persistence. EJB servers are based on the Java™ 2 Platform, Enterprise Edition (J2EE™).

An EJB server creates an infrastructure for deploying applications that are usually called components. The components are written in object programming languages such as Java, C#, C++, and others. Components used in the middle tier are a common way to realize the high-level abstractions of business processes and workflow.

An EJB server sits below a Web server and can have:

	Access to external Web Services. This could be virtually anything.
	Access to other Internet resources. This also could be most anything: weather reports, currency converters, news feeds, and so on.
	Access to internal Web Services. An example of an internal Web Service might be the validation of an account based on data input over the Internet/Intranet and data stored in an existing database.
	Access directly to internal system directly, bypassing Web Services. Direct access to an existing database might be an example of this access.

You should consider an EJB server when you have a need for:

	Integration with existing systems and databases
	Web site support

Secondary reasons to use EJB servers derive from the primary reasons. A few secondary reasons are:

	E-Commerce
	Web-integrated collaboration
	Component re-use

One way to look at EJB servers is that they are a formalization of a solution to a problem that has been around for a long time. That problem can characterized as a need to create an integrated presentation and processing environment for existing systems and databases. The presentation has pretty much been decided with browsers now being the dominant interface. This is why you usually see a Web server paired with or included in an EJB server. The integrated processing has been moving towards components for some time. EJB servers provide containers for such components along with application program interfaces (APIs) to support the components. These APIs are to the existing systems and databases.

EJB server articles

Interested in how EJB servers can help you with with enterprise integration? What are some architectures that take advantage of these products yet preserve your existing investment in your software architecture? These free, online articles provide answers to these questions and more. Check out the articles on EJB servers.

EJB server product comparison

A free comparison was published in May 2001. Click here for more information.

Vendors and products

A listing of EJB server vendors with links to their respective Web sites is available on this site. Click here for EJB server vendors.