In SCA, applications are packaged in one or more contributions. Contributions can be a variety of formats. Fabric3 supports the following formats and can be extended to support others:
- JAR archives
- ZIP archives
- WAR archives
- OSGi bundles
- XML documents
JAR Contributions
Most SCA applications will be packaged as one or more JARs. In addition to including application classes and artifacts, a JAR-based contribution may contain an sca-contribution.xml manifest file in the META-INF
directory. The manifest file contains contribution metadata, including a list of deployable composites. Deployable composites are those composites that are contained in the contribution which are to be deployed to a domain. A contribution may contain other composites but if they are not marked as deployable, they may not be directly included in the domain (i.e. they may only be used by a deployable composite). An example sca-contribution.xml file is shown below:
<contribution xmlns="http://docs.oasis-open.org/ns/opencsa/sca/200912" xmlns:sample="urn:tempuri.org"> <deployable composite="sample:TheComposite"/> </contribution>
Applications often require third-party libraries. Fabric3 supports two ways of packaging and deploying these libraries: by embedding them in the JAR; and importing them from another contribution. Similar to WARs, Fabric3 allows contribution JARs to bundle third-party libraries by placing their JARs in the META-INF/lib directory of the contribution. Any JAR placed in the META-INF/lib directory will be made available on the contribution classpath.
WAR Contributions
Fabric3 supports packaging contributions as WAR files. WAR contributions behave like JAR contributions except the SCA manifest in is placed in WEB-INF
. In addition, libraries and classes in WEB-INF/lib
and WEB-INF/classes
respectively are placed on the contribution classpath. WAR contributions are used for deploying web applications to a domain.
ZIP Contributions
ZIP contributions are identicle to JAR contributions.
OSGi Bundles
Fabric3 also supports packaging contributions as OSGi bundles. In this case, OSGi bundle manifests may be used to export and import packages from other contributions. An SCA manifest file is not required.
Note Export-Package and Import-Package OSGi manifest headers are supported in a limited fashion. Specifically, attribute directives are not supported.