I followed the solution in the following link, and it works fine:
Access Spring beans from a servlet in JBoss
public class MyServlet extends HttpServlet {
@Autowired
private MyService myService;
public void init(ServletConfig config) {
super.init(config);
SpringBeanAutowiringSupport.processInjectionBasedOnServletContext(this,
config.getServletContext());
}
}