[Version 5.0.2 and later]Welcome to applications

Note: PDF versions of this documentation are available You can browse PDF versions of this documentation using your Adobe Reader . See the Applications PDF files available from www.ibm.com/software/webservers/appserv/infocenter.html .

In the WebSphere Application Server environment, the components making up a Java 2 Platform, Enterprise Edition (J2EE) application are referred to as application modules, specifically:

You can deploy both Web and EJB modules as stand-alone applications. A J2EE application is generally comprised of all three application modules, each deployed in its own container that is provided by the application server that you have configured. The following diagram depicts how the application modules interact across the three-tier architecture of enterprise computing:

Application module interaction diagram

The diagram does not depict interaction between Web modules and the thin application, pluggable, or J2EE application client because it is a rare requirement. Applications that use these client types, however, can incorporate Web modules. The product provides different levels of support for the requirement, according to client type. Refer to articles specifically on your client type for more information.

The following sections give introductory descriptions of the different modules, as well as the additional services and APIs that the product makes available for your enterprise applications.

Web modules

A Web module consists of the following components, in varying combinations (corresponding to the application client requirements, security requirements, and so on):

Product extensions to the open source servlet and the JSP APIs enhance standard features, and provide additional functionality. For example, the session manager service gives you powerful personalization capabilities for Web pages. To learn more, refer to Welcome to Web modules.

EJB modules

EJB modules are combinations of enterprise beans, which perform various roles in retrieving data from the Data and Resource tier and running business logic in a J2EE application. You also can deploy an EJB module as a stand-alone application (refer to Deploying and managing applications for the necessary steps).

WebSphere Application Server supports enterprise beans built upon a broad range of specifications, from the current 2.0 specifications to 1.1 coding. For more information about EJB version support, see Welcome to EJB modules. For more information about the types of enterprise beans, see the Enterprise beans article.

Client modules

WebSphere Application Server supports multiple models of a client module, each suitable for different types of applications. For example: the various dependencies of the models on Web modules for access to business logic can accommodate different client-side requirements for deployment. If a developer wants to create an application requiring no initial code deployment to client machines, an appropriate client module choice is the applet client. This client receives the necessary application code through download from HTML pages.

For more information about each model, refer to Welcome to Client modules.

Web services

Web services technologies enable applications to interact with one another across the Internet. If you have an existing application and you want to make the service that your application provides available to others, either within your own organization or beyond it, you can use Web services technologies to provide a standard Web interface for your service.

For additional information, refer to Welcome to Web services.

CORBA applications[5.0 only][Version 5.0.1][Version 5.0.2]

In addition to J2EE enterprise applications, you can also deploy CORBA client/server applications in your environment (if your environment includes the CORBA C++ SDK). You can use the CORBA C++ SDK to build a lightweight WebSphere CORBA server to use with new or existing C and C++ programs. You also can use the SDK to build a WebSphere CORBA C++ client to use with a WebSphere EJB server or WebSphere CORBA C++ server.

Application services

IBM WebSphere Application Server provides essential services to ease the building of dynamic and flexible e-business applications. These services support and extend the open standards of J2EE and Web services, with a focus on application reuse and integration. For example, Naming services provide a convenient way of granting clients access to objects that are associated with applications installed on Application Server.

Still other features of the product take application services to the next level, providing a broad range of dynamic API extensions that address functional gaps in the J2EE programming model. For example, using the object pool manager you can designate which objects you want an application to pool during run time to reduce the costs of frequent garbage collection and object construction, potentially improving application performance.

For more information, refer to Welcome to Application services.

Process choreographer

Process choreographer is a powerful enterprise workflow tool that supports running Business Process Execution Language (BPEL) processes in a J2EE environment. These processes can be used to integrate J2EE resources, Web services, and activities that require human interaction.

For more information, refer to Welcome to process choreographer.

Assembly tools

To convert your various application components into a deployable format, you first assemble them into the three larger application modules. You then assemble the modules into a single enterprise application archive (EAR) file.

[5.0 only][Version 5.0.1][Version 5.0.2]The Application Assembly Tool and a command line deployment tool are provided for these assembly processes. For more information, refer to Welcome to Assembly tools.

Deployment

Deploying is the activity in which applications are placed onto application servers, without needing to customize the application code for each server environment. The WebSphere Application Server administrative console is one of the tools that you can use to install your modules onto the Application Server, and then manage the installed modules in their respective containers.

For more information, refer to Deploying.


Related concepts
Three-tier architectures



Searchable topic ID:   welc_apps
Last updated: Jun 21, 2007 8:07:48 PM CDT    WebSphere Business Integration Server Foundation, Version 5.0.2
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