spring data jpa save方法会重复插入数据

Question

源代码：

    //控制层
    @ResponseBody
    @PostMapping("/doRegister")
    public JSONObject  register(String userName,String password,String email,String code,HttpServletRequest request,HttpServletResponse response){
        JSONObject result  = new JSONObject();
        result.put("err", 1);
        HttpSession session = request.getSession(true);
        String verCode = (String)session.getAttribute(CODE_NAME);
        if(!verCode.equalsIgnoreCase(code)){
            result.put("msg", "验证码输入错误");
            //怀疑是这里的判断导致了重复数据问题 
        }else if(bbsUserService.hasUser(userName)){
            result.put("msg", "用户已经存在");
        }else{
            BbsUser user = new BbsUser();
            user.setBalance(10);
            user.setLevel(1);
            user.setScore(10);
            user = bbsUserService.setUserAccount(user);
            WebUtils.loginUser(request, response, user, true);
            result.put("err", 0);
            result.put("msg", "/bbs/index");
        }
        return result;
    }

//服务层
@Service
public class BbsUserServiceImpl implements BbsUserService {
    @Override
    @Transactional
    public BbsUser setUserAccount(BbsUser user) {
        String pwd = HashUtil.generatePwd(password);
        user.setPassword(pwd);
        return bbsUserRepository.save(user);
    }
    //试过不同的写法
    @Override
    public boolean hasUser(String userName) {
//        return bbsUserRepository.existsByUserName(userName);
        BbsUser byUserName = bbsUserRepository.findByUserName(userName);
        return byUserName == null ? false:true;
    }
}

但是有时候运行的时候会有两条插入语句，偶尔又会没有。不知道为什么。

Hibernate: insert into bbs_user (balance, corp, email, level, password, score, user_name) values (?, ?, ?, ?, ?, ?, ?)
Hibernate: insert into bbs_user (balance, corp, email, level, password, score, user_name) values (?, ?, ?, ?, ?, ?, ?)

有没有遇到过同样问题的，或者有什么思路。。求解/(ㄒoㄒ)/~~

Answer 1

偶尔出现的话，我猜是你前端没有做重复点击的处理

Answer 2

同意楼上的说法。具体验证你可以在Controller上打个断电或者日志，看看是否存在多次调用的情况

Answer 3

如果连自动生成的id都是重复的呢？
@Dylan