Introduction of three main EJB container application servers

After the launch of the EJB specification by Sun, there has been a great response from many companies and developers.

It is very easy to develop an enterprise application system with Java. Many companies have already launched or are planning to EJB products. EJB has become the focus of Java technology research.

Sun's definition of EJB is that EJB is a cross-platform component architecture for developing and deploying multi-tier, distributed, object-oriented Java application Systems. Using EJBS makes it easy to develop commercial application systems that can be developed in an EJB-enabled environment and deployed in other environments as requirements change, and applications can migrate to other, more powerful and complex servers without modification.

In the EJB specification, the 6 roles are mentioned, including the bean provider, the application assembler, the EJB container, the EJB Configuration tool, the EJB service provider, and the system administrator. Within this, the EJB container is the core of the EJB's ability to run. The EJB container manages the important core tasks of creating, undoing, activating, living, and connecting to the database.

The emergence of EJB specification has played a great role in promoting the development of e-commerce. Now large-scale e-commerce sites, are the use of EJB technology application server to build. Now the most widely used, EJB-enabled application servers are three: IBM's Websphere,bea-weblogic,inprise IAS. In addition, there are some relatively small, can be given to do research and learning with OPENEJB.

First, let's look at IBM's WebSphere:

The IBM WebSphere Application Server is a complete, open Web application server. It is the core of IBM E-business application architecture. The WebSphere application Server offers three levels of versions: standard (Standard Edition), Advanced (Advanced Edition), Enterprise (Enterprise Edition). Among them, the programming model that supports EJB is started in the Advanced edition. Provide a highly reliable solution in the Enterprise Edition that enables it to migrate to a critical enterprise environment. WebSphere is also one of the best in the Chinese market for these products. Not only held a lot of competitions, held a lot of lectures, but also with many domestic colleges and universities, free gift of many sets of WebSphere kits. So, WebSphere is the most used in China.

EJB is one of the most core object technologies of WebSphere, it provides a server-side Java component with transaction function, and it is also a new object distributed technology programming model. Applications completed with EJB components will support more advanced transaction processing capabilities based on the database, such as updates between multiple databases, two-phase submissions, and so on.

Most crucially, WebSphere is IBM's entire suite of development, application servers. He combines EJB with IBM's other excellent products (txserise and component Broker). In specific applications, based on security considerations, performance considerations and System management considerations, you can also add Firewall,webshpere performance packs and Tivoli. So maybe IBM's EJB container is not necessarily the best, but the combination of EJB in WebSphere and IBM's other products is the best.

With Visual age in the Toolset, you can quickly develop an EJB component and then deploy it in WebSphere Application server, where you can quickly develop an e-commerce platform through the integration of Apache (WEB server). There is a "money" in the country.

Then we'll take a look at Bea's WebLogic:

As early as this July, BEA announced that the company had pioneered support for the Enterprise JavaBeans (EJB) 2.0 standard. While the EJB2.0 specification is currently the highest in the Java enterprise-level development industry, BEA's pioneering support for EJB2.0 once again consolidates the company's undisputed leadership in Java applications and strengthens the market position of BEA WebLogic as the main platform for EE technology.

BEA supports EJB2.0 by providing an add-on package for Bea WebLogic Server 5.1. With the support of the BEA WebLogic server for EJB2.0, BEA can help developers quickly launch e-business applications, thereby enabling developers to benefit greatly from the industry's latest standards.

As the cornerstone of the industry standard and JAVA2 platform for server-side business logic, Enterprirse JavaBeans is the main technology for the BEA WebLogic application server. Enterprise JavaBeans enables developers to concentrate on developing business logic for their application systems and e-business scenarios without being distracted by the infrastructure architecture. With support for EJB2.0, the BEA WebLogic Application Server family provides a de facto standard infrastructure to help users quickly develop and deploy next-generation e-business and enterprise applications.