Business-level applications aggregates application resources into a configuration artifact, similar to a server or cluster, stored in WAS configuration repository.
A business-level application does not contain application binary files, rather, it lists composition units, which represent the application binary files.
Administration of binary files is separate from administration of the application definition.
A business-level application supports recursive composition by reference that facilitates hierarchical assembly of business-level applications and individual deployed artifacts within or outside a WebSphere product. The composition at its lowest level consists of configured instances of application binary files that run in a specific runtime environment such as an appserver.
JAR and EAR files deliver the business logic.
A business-level application does not introduce new programming, runtime, or packaging models:
- You do not need to change the application business logic. The business-level application function does not introduce new APIs.
- You do not need to change the application runtime settings. The product supports all of the runtime characteristics, such as security, class loading and isolation, required by individual models to which business components are written.
- You do not need to change the application packaging. There is no specific unique packaging model that provides a business-level application definition.
Typically, you first create an empty business-level application and then add composition units to it. The business-level application name must be unique within a cell. The business level application itself has minimal configuration data associated with it, solely the list of composition units, but individual composition units might save application-specific configuration data.
A business-level application is defined in WAS configuration repository under APP_ROOT/cells/cell_name/blas/business_level_application_name/bver/BASE/bla.xml.
Comparisons to Java EE applications
Business-level applications can consist of or aggregate Java EE applications and modules with non-Java EE artifacts. The contents of Java EE applications integrate with business-level application concepts for deployment and management of applications. Existing Java EE application management APIs continue to work after you add Java EE application or modules to a business-level application. The business-level application management API accepts Java EE contents and configurations and delegates to existing Java EE management APIs. Control operations such as starting and stopping a Java EE composition unit are delegated to ApplicationManager MBean on appservers that start and stop Java EE applications.
Table 1. Java EE concepts compared to business-level application concepts
Java EE concept Business-level application concept Description EAR or stand-alone module for deployment Asset Java EE application contents are assets. Java EE application created at the end of application install Composition unit A Java EE application is in an EAR file. WAS ND v7.0 saves the EAR file in WAS repository as a composition unit. Java EE modules within the EAR file Deployable units in the asset Each module in the EAR file is a deployable unit that we can install on independent deployment targets. The EAR file is still managed as a single asset in its entirety. Java EE application installation using the admin console, programming, or wsadmin commands Multiple business-level application management commands
During Java EE application deployment, we can specify the name of the business-level application to include the Java EE application. If the business-level application name is not set, WAS creates a default business-level application with the same name as the Java EE application name. WAS ND v7.0 adds a composition unit with the same name as the Java EE application name under the business-level application. We can deploy multiple Java EE applications under a single business-level application.
We can make a Java EE application a business-level application and add it to another business-level application:
- Install the Java EE application (EAR file) using the enterprise application installation console wizard, programming, or wsadmin. Keep the default selection to create a business-level application that has the same name as the Java EE application.
- Create an empty business-level application.
- Add the EAR file business-level application to the empty business-level application. The EAR file business-level application is a composition unit of the containing business-level application.
Or, we can make a Java EE application an asset and add it to another business-level application:
- Import an EAR file as an asset. It has an asset type aspect of Java EE ear.
- Create an empty business-level application.
- Add the Java EE application asset to the business-level application. The EAR file asset is a composition unit of the containing business-level application.
- Collect targets for each deployable unit (Java EE module).
Uninstall Java EE application Multiple business-level application management commands You delete the Java EE application composition unit from the business-level application:
Start the Java EE application. Start the composition unit. Starting a business-level application starts any Java EE application in it. Stop the Java EE application. Stop the composition unit. Stopping a business-level application stops any Java EE application in it.
Deploy business-level applications