When a singleton EJB bean class implements javax.ejb.SessionBean interface,

this interface should be removed from the implements clause; and all methods declared in javax.ejb.SessionBean interface (see below) that are implemented in the bean class or its super classes should be checked for @Override annotation, and remove this annotation too if present.

Methods declared by javax.ejb.SessionBean interface:

void setSessionContext(SessionContext ctx);

void ejbRemove();

void ejbActivate();

void ejbPassivate();