ejb-development-lifecycle

Building an EJB component involves more than just writing Java code. You need to compile, package, configure, and deploy—missing any step results in a non-functional component. What’s the correct order?

The EJB development lifecycle is an 8-step process from raw Java files to a running, tested component in the container. Each step has a specific purpose and must be done in order.

1. Write Java files: Component interfaces, home interfaces, bean class, helper classes
2. Write deployment descriptor: ejb-jar.xml with bean metadata (or use IDE/XDoclet to generate)
3. Compile: javac to convert .java → .class
4. Create EJB-JAR: Use jar utility to package .class files + ejb-jar.xml
5. Deploy: Copy JAR to container’s deployment folder or use vendor tools
6. Configure: Set database connections, thread pools via vendor console/config files
7. Start container: Verify the JAR loaded successfully
8. Test: Write a client, generate stubs, compile, run, and verify

• Standardized process: Every EJB component follows these steps (vendor-neutral)
• Step 5 is vendor-specific: Each container has its own deployment mechanism
• Step 6 is vendor-specific: Configuration differs (Web console vs config files)
• Deployment descriptor is key: Tells container how to manage the bean

• Built from: Deployment Descriptor, Home Interface, Remote Interface
• Builds into: EJB Object (generated in step 5), EJB Container
• Related: EJB-JAR File (output of step 4)
• Contrasts with: Simple Java app (just compile and run—no deployment descriptor needed)

• Forgetting step 2: Without ejb-jar.xml, container doesn’t know about your beans
• Classpath issues: Step 3 needs EJB APIs (javax.ejb.*) in classpath
• Vendor tools automate: Modern IDEs (Eclipse, IntelliJ) automate steps 2-4