休眠@Transactional

Question

我是hibernate新手，如何在spring中使用@Transactional，

这是inf类，

@Transactional(propagation = Propagation.REQUIRES_NEW, rollbackForClassName = {
"com.framework.exceptions.ApplicationException" })
public ServiceObject create(ServiceObject dtObject) throws ApplicationException;

@Transactional(propagation = Propagation.REQUIRES_NEW, rollbackForClassName = {
        "com.framework.exceptions.ApplicationException" })
public ServiceObject update(ServiceObject dtObject) throws ApplicationException;

实现类，

public ServiceObject read(ServiceObject dtObject) throws ApplicationException {
    try {

            if (dtObject.getDataObject() != null) {
                CustomersEntity customersEntity = (CustomersEntity) dtObject.getDataObject();
                String captchaStr = customersEntity.getCaptchaString();
                if (captchaStr != null && !captchaStr.isEmpty()) {
                    customersEntity.setCaptchaType(captchaStr.split(",", 2)[0]); 
                    customersEntity.setCaptcha(captchaStr.split(",", 2)[1].getBytes());
                    customersEntity.setCaptchaString(null);
                    customersEntity.setUpdatedOn(DateUtil.getISTTodayDate());
                    if(customersEntity.getResult() == null || customersEntity.getResult().isEmpty()){
                        customersEntity.setWip((byte) 0); // if user not submit the captcha value
                    }
                    dtObject.setDataObject(customersEntity);
                    update(dtObject);

                    CustomersEntity customersEntity2 = (CustomersEntity) dtObject.getDataObject();
                    customersEntity2.setUserId(customersEntity2.getSolvedBy());
                    customersEntity2.setUpdatedOn(DateUtil.getISTTodayDate());
                    dtObject.setDataObject(customersEntity2);
                    CustomersEntity customersEntity3 = getCaptcha(dtObject);
                    if (customersEntity3 != null) {
                        byte[] imgByte = customersEntity3.getCaptcha();
                        customersEntity3
                                .setCaptchaString(customersEntity3.getCaptchaType() + "," + new String(imgByte));
                        customersEntity3.setWip((byte) 1);
                        customersEntity3.setUpdatedOn(DateUtil.getISTTodayDate());
                        dtObject.setDataObject(customersEntity3);
                        update(dtObject);
                    } else {
                        dtObject.setMessage("No captcha, please try again after some time.");
                        dtObject.setSuccess(false);
                    }
                } else {
                    dtObject.setMessage("Pls try again.");
                    dtObject.setSuccess(false);
                }
            }

    } catch (Exception e) {
        dtObject.setSuccess(false);
        throw new ApplicationException(e.getMessage(), e);
    }
    return dtObject;
}

@Override
public ServiceObject update(ServiceObject dtObject) throws ApplicationException {
    try {
            customersDao.update((CustomersEntity) dtObject.getDataObject());
            dtObject.setMessage("Record updated successfully.");
            dtObject.setSuccess(true);

    } catch (Exception e) {
        dtObject.setSuccess(false);
        throw new ApplicationException(e.getMessage(), e);
    }
    return dtObject;
}

调用 read(...) 方法时，内部调用了 update(...) 方法两次，但结果将是单个表中不同行的两次不同更新，但更新错误。

那么，我该如何使用@Transactional 注释。

请帮我解决这个问题。

Answer 1

它是否更新了同一行而不是两个不同的行？如果这就是您所说的错误，那么请考虑 @Transactional 注释定义了附加到持久性上下文的单个事务的范围。

因此，当您使用相同的对象、设置或更改时，假设对象的不同属性，底层 JPA 检测到它基本上是您尝试更新的相同对象。因此，不是两个更新查询，而是只运行一个最新/最后一个更新语句，并且只有该更改才会反映在数据库中。