EJBHomeFactory factory = EJBHomeFactory.getFactory();
Object ejbHome = factory.lookUpHome( "MaterialSort" );
在EJBHomeFactory中
        public Object lookUpHome(String jndi){
          try {
            return ctx.lookup(jndi);
          }
          catch (NamingException ex) {
            ex.printStackTrace();
            return null;
          }
        }执行到ctx.lookup(jndi)失败