ApplianceManagerConnectorEntityMgr.java 文件源码

public static boolean isManagerTypeUsed(String managerType, EntityManager em) {

        try {
            CriteriaBuilder cb = em.getCriteriaBuilder();
            CriteriaQuery<Long> cq;
            Root<?> from;

            cq = cb.createQuery(Long.class);
            from = cq.from(ApplianceManagerConnector.class);
            cq = cq.select(cb.count(from))
                    .where(cb.equal(from.get("managerType"), managerType));

            Long count1 = em.createQuery(cq).getSingleResult();

            cq = cb.createQuery(Long.class);
            from = cq.from(Appliance.class);
            cq = cq.select(cb.count(from))
                    .where(cb.equal(from.get("managerType"), managerType));

            Long count2 = em.createQuery(cq).getSingleResult();

            return count1 > 0 || count2 > 0;
        } catch (Exception e) {
            return true;
        }

    }