报错信息：
    org.springframework.dao.InvalidDataAccessApiUsageException: EntityManager is closed; nested exception is java.lang.IllegalStateException: EntityManager is closed
    at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:381)
    at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:246)
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:488)
    at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:59)
    at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213)


原因是代码中query有多次读取操作如：（query.getResultList()），query在读取一次之后会自动关闭，

原代码：

    public List<Map<String, Object>> selectUserInfo(String userId) {
        StringBuilder sql = new StringBuilder(" select user_id as userId,mobile  ");
        sql.append(" from user_info ");
        sql.append(" where user_id = :userId");
        Query query = entityManager.createNativeQuery(sql.toString());
        query.setParameter("userId", userId);
        if (query.getResultList() != null && query.getResultList().size() > 0) {
            // 将结果转化为 Map<column, value>
            query.unwrap(SQLQuery.class).setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP);
            return query.getResultList();
        }
        return null;
    }

修改之后：

	public List<Map<String, Object>> selectUserInfo(String userId) {
        StringBuilder sql = new StringBuilder(" select user_id as userId,mobile  ");
        sql.append(" from user_info ");
        sql.append(" where user_id = :userId");
        Query query = entityManager.createNativeQuery(sql.toString());
        query.setParameter("userId", userId);
        // 将结果转化为 Map<column, value>
        query.unwrap(SQLQuery.class).setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP);
        return query.getResultList();
    }

对比可以发现query.getResultList();查询只触发一次，就不会出现EntityManager is closed;的问题了，