Application assembly and J2EE applications
Application assembly is the process of creating an enterprise archive (EAR) file containing all files related to an application, as well as an XML deployment descriptor for the application. This configuration and packaging prepares the application for deployment onto an appserver.
EAR files are comprised of the following archives:
- Enterprise bean JAR files (known as EJB modules)
- WAR files (known as Web modules)
- Application client JAR files (known as client modules)
- Resource adapter archive (RAR) files (known as resource adapter modules)
- SAR files (known as Session Initiation Protocol (SIP) modules)
Ensure that modules are contained in an EAR file so that they can be deployed onto the server. The exceptions are WAR modules, which you can deploy individually. Although WAR modules can contain regular JAR files, they cannot contain the other module types described previously.
The assembly process includes the following actions:
- Selecting all of the files to include in the module.
- Creating a deployment descriptor containing instructions for module deployment on the appserver.
As you configure properties using an assembly tool, the tool generates the deployment descriptor for you. While the Application Server Toolkit or Rational Application Developer graphical interface is recommended, you can also edit descriptors directly in your favorite XML editor.
- Packaging modules into a single EAR file, which contains one or more files in a compressed format.
As part of the assembly process, you might also set environment-specific binding information. These bindings are defaults for an administrator to use when installing the application through the console. Further, you might define IBM extensions to the J2EE specification, such as to allow servlets to be served by class name. To ensure portability to other appservers, these extensions are saved in an XML file that is separate from the standard J2EE deployment descriptor.
Related concepts
Assembly tools
Related tasks
Assembling applications