3.2. Add an Explicit Module Dependency to a Deployment
This task shows how to add an explicit dependency to an application. Explicit module dependencies can be added to applications to add the classes of those modules to the class path of the application at deployment.
Some dependencies are automatically added to deployments by JBoss EAP 6. See Section 3.8.1, “Implicit Module Dependencies” for details.
Prerequisites
- You must already have a working software project that you want to add a module dependency to.
- You must know the name of the module being added as a dependency. See Section 3.8.2, “Included Modules” for the list of static modules included with JBoss EAP 6. If the module is another deployment then see Section 3.1.7, “Dynamic Module Naming” to determine the module name.
Dependencies can be configured using two different methods:
- Adding entries to the
MANIFEST.MFfile of the deployment. - Adding entries to the
jboss-deployment-structure.xmldeployment descriptor.
Procedure 3.1. Add dependency configuration to MANIFEST.MF
Maven projects can be configured to create the required dependency entries in the
MANIFEST.MF file. See Section 3.3, “Generate MANIFEST.MF entries using Maven”.
Add
MANIFEST.MFfileIf the project has noMANIFEST.MFfile, create a file calledMANIFEST.MF. For a web application (WAR) add this file to theMETA-INFdirectory. For an EJB archive (JAR) add it to theMETA-INFdirectory.Add dependencies entry
Add a dependencies entry to theMANIFEST.MFfile with a comma-separated list of dependency module names.Dependencies: org.javassist, org.apache.velocity
Optional: Make a dependency optional
A dependency can be made optional by appendingoptionalto the module name in the dependency entry.Dependencies: org.javassist optional, org.apache.velocity
Optional: Export a dependency
A dependency can be exported by appendingexportto the module name in the dependency entry.Dependencies: org.javassist, org.apache.velocity export
Procedure 3.2. Add dependency configuration to jboss-deployment-structure.xml
Add
jboss-deployment-structure.xmlIf the application has nojboss-deployment-structure.xmlfile then create a new file calledjboss-deployment-structure.xmland add it to the project. This file is an XML file with the root element of<jboss-deployment-structure>.<jboss-deployment-structure> </jboss-deployment-structure>
For a web application (WAR) add this file to theWEB-INFdirectory. For an EJB archive (JAR) add it to theMETA-INFdirectory.Add dependencies section
Create a<deployment>element within the document root and a<dependencies>element within that.Add module elements
Within the dependencies node, add a module element for each module dependency. Set thenameattribute to the name of the module.<module name="org.javassist" />
Optional: Make a dependency optional
A dependency can be made optional by adding theoptionalattribute to the module entry with the value oftrue. The default value for this attribute isfalse.<module name="org.javassist" optional="true" />
Optional: Export a dependency
A dependency can be exported by adding theexportattribute to the module entry with the value oftrue. The default value for this attribute isfalse.<module name="org.javassist" export="true" />
Example 3.3. jboss-deployment-structure.xml with two dependencies
<jboss-deployment-structure>
<deployment>
<dependencies>
<module name="org.javassist" />
<module name="org.apache.velocity" export="true" />
</dependencies>
</deployment>
</jboss-deployment-structure>
JBoss EAP 6 will add the classes from the specified modules to the class path of the application when it is deployed.
