ejb-jar-file

You’ve written your bean class, interfaces, and deployment descriptor. How do you package them for deployment to any EJB container? You need a standard format that bundles everything together.

The EJB-JAR file is a standard Java archive (.jar) containing all the classes (bean class, home/remote/local interfaces, helpers) plus the ejb-jar.xml deployment descriptor. This single file is what you deploy to the container—it’s vendor-neutral and portable.

1. Compile: javac converts .java → .class for all your files
2. Package: jar cvf MyBean.jar *.class ejb-jar.xml creates the archive
3. Deploy: Copy JAR to container’s deployment folder or use vendor tools
4. Container verifies: Checks the JAR structure and generates EJB Object/Home Object

• Standard format: Any EJB container can read an EJB-JAR file
• Contains: Classes + META-INF/ejb-jar.xml (deployment descriptor)
• Optional: May include META-INF/webservices.xml or vendor-specific files
• Vendor-neutral: Write once, deploy on any EJB container

• Built from: Home Interface, Remote Interface, Deployment Descriptor
• Builds into: EJB Verification & Generation (container processes the JAR)
• Related: EJB Client JAR (subset of files for clients)
• Contrasts with: Regular JAR (no ejb-jar.xml, not deployable to EJB container)

• Missing ejb-jar.xml: Container rejects the JAR—deployment fails
• Classpath issues: All dependencies must be in the JAR or server classpath
• Vendor-specific files: Some containers need extra files in META-INF/ (e.g., weblogic-ejb-jar.xml)