Select the implementation type for an SCA composite
A benefit of Service Component Architecture (SCA) is that we can use existing assets in an application, without having to change the asset implementation. Many enterprises have application assets developed using a variety of technologies and frameworks, including assets previously deployed in a WAS environment, which is predominantly Java EE or Java-centric. SCA supports several service implementation technologies.
Determine which application files or artifacts (assets) to deploy in an SCA application. If necessary, develop the files or artifacts.
We can use SCA composites to:
- Reuse existing service implementations in the definition of an SCA component for use in an SCA composite application.
- Enable the services within those technologies to be exposed or use a service over the supported access bindings without changing the business logic of the service.
Each component within an SCA assembly specifies the implementation technologies which provide the specific business logic which implements the services described in the component definition. A composite is composed of 1-to-many components, each of which can be made up of differing implementation technologies.
SCA supports the following implementation programming model technologies. The product supports all of these implementation types on OSOA but does not support the implementation types OSGi, Java EE (JEE), Spring, or Widget on OASIS.
- implementation.java
- The implementation conforms to the SCA Java Component Implementation specification.
- implementation.composite
- The implementation conforms to an SCA composite as defined in the SCA Assembly Model specification.
- implementation.web
- The implementation conforms to Java EE 1.5 for Web modules and Web archive (WAR) files.
- implementation.ejb
- The implementation conforms to Java EE 1.5 for EJB 2.1 and 3.0 Stateless Session Beans.
- implementation.jee
- The implementation conforms to Java EE 1.5 for EAR files.
- implementation.osgiapp
- The implementation conforms to the OSGi application programming model as supplied in the product.
- implementation.spring
- The implementation conforms to the SCA Spring Component Implementation specification.
WAS does not include the Spring 2.5.5 package. We must obtain the Spring 2.5.5 package from the supplying vendor.
- implementation.widget
- The implementation is SCA-enhanced JavaScript contained within an HTML page. Unlike the other implementation types, this component runs on the server but it is returned to browsers from the server. You wire services that JavaScript code references through SCA bindings.
- Select the implementation type to use for the SCA component.
SCA implementation types. Based on the implementation technology of an asset, select the SCA implementation type to use
Asset implementation technology SCA implementation type SCA Java implementation.java SCA assembly implementation.composite Java EE application (EAR) implementation.jee Java EE EJB module, session bean, or message-driven bean implementation.ejb Java EE Web module in a Java EE application implementation.web Enterprise bundle archive (EBA) artifact that uses OSGi bundles and Blueprint components implementation.osgiapp Bean that follows the Java 2 Platform, Standard Edition (J2SE) programming model in a Spring 2.5.5 container. implementation.spring HTML page enriched with JavaScript code containing SCA for return to a browser. An SCA service returns data in JavaScript. The data can be in Atom collections or in JavaScript Object Notation (JSON) format. implementation.widget
- Configure the binding for the selected implementation type and use the binding in an SCA component or application.
See topics in the related links for information on specifying implementations and bindings.
Results
The SCA composite makes the appropriate environmental transitions to connect the implementation technology to any exposed bindings that are also in the composite definition.
What to do next
Deploy the SCA composite or application in a business-level application.
Related concepts
SCA application package deployment Import assets
Related tasks
Develop Service Component Architecture (SCA) services Use existing Java EE modules and components as SCA implementations Use OSGi applications as SCA component implementations Use Widget implementation in JavaScript with Atom or HTTP bindings Deploy OSGi applications that use SCA