Stateless Session Bean

Do I package a stateless session bean in a war file or a ear file for deploy开发者_C百科ment?

Neither nor. EJBs belong in standard JAR files (with a META-INF/ejb-jar.xml). In order to use EJBs from a WAR you pack these two archives in an EAR.

Since this is not really convenient it's possible since EJB 3.1 to package EJBs in the WAR.

Stateless Session Beans (SLSB) are packaged in an EJB-JAR (which is a regular JAR file) including or not an optional deployment descriptor. EJB-JARs and WARs are assembled in an EAR for deployment.

See this article by Debu Panda and Rezza Rahmann (which is actually an extract from the excellent EJB 3 in Action):

• Packaging EJB 3 Applications

With EJB 3.1/Java EE 6 you don't need EAR files any more, you can also put your session beans directly in a WAR file (as a separate .class file in WEB-INF/classes, or inside a JAR file within the WAR file's WEB-INF/lib directory). See e.g. http://java.sun.com/developer/technicalArticles/JavaEE/JavaEE6Overview_Part3.html#simpack