如何隔离单个删除(..)在grails 2.5.6中的运行时异常期间被回滚？

import org.springframework.transaction.PlatformTransactionManager
import org.springframework.orm.hibernate4.HibernateTransactionManager

beans = {
    transactionManager(HibernateTransactionManager) {
        sessionFactory = ref('sessionFactory')
    }
}

import org.springframework.transaction.annotation.Transactional

@Transactional
def deleteItem(Long itemId) {
    // 删除操作的代码
}