try {
    return dao.updateBanana(d);
}catch(DeadlockLoserDataAccessException e) {
    logger.error("An unexpected error occurred for userId {} , exception : {}.",userId,e.getMessage());
    try {
        //增加出错重试,在产生死锁的异常中,重试可能有很大几率成功
        return dao.updateBanana(d);
    }catch (DeadlockLoserDataAccessException ex) {
        logger.error("An unexpected error occurred for userId {} again, exception : {}.",userId,e.getMessage());
        return 0;
    }
}

最简单的重试机制