Erro hibernate

protected SessionFactory getSessionFactory() {
		try {
			return (SessionFactory) new InitialContext()
					.lookup("SessionFactory");
		} catch (Exception e) {
			log.error("Could not locate SessionFactory in JNDI", e);
			throw new IllegalStateException(
					"Could not locate SessionFactory in JNDI");
		}
	}

java.lang.IllegalStateException: Could not locate SessionFactory in JNDI
	beans.TbEventosHome.getSessionFactory(TbEventosHome.java:31)
	beans.TbEventosHome.<init>(TbEventosHome.java:23)
	struts.InserirEventoAction.execute(InserirEventoAction.java:62)
	org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
	org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
	org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
	org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:802)