JBoss :: Professional Open Source
import org.jboss.security.SubjectSecurityManager;
   InitialContext ctx = new InitialContext();
   Context envCtx = (Context) ctx.lookup("java:comp/env");
   SubjectSecurityManager ssm = (SubjectSecurityManager) envCtx.lookup("security/security-domain");
	
If you just want the name, use: 
Code: 
   InitialContext ctx = new InitialContext();
   Context envCtx = (Context) ctx.lookup("java:comp/env");
   LinkRef ref = (LinkRef) envCtx.lookupLink("security/security-domain");
   String secDomain = ref.getLinkName();