[英]Spring @Transactional TransactionRequiredException or RollbackException
I have read a lot of @Transactional annotation, I saw stackoverflow answers but it does not help me. 我已经阅读了很多@Transactional批注,我看到了stackoverflow的答案,但对我没有帮助。 So I am creating my question.
所以我要提出我的问题。
My case is to save user with unique email. 我的情况是用唯一的电子邮件保存用户。 In DB I have user with email xxx@xxx.com, and I am saving user with the same email address.
在数据库中,我有一个使用电子邮件xxx@xxx.com的用户,并且正在使用相同的电子邮件地址保存该用户。 For saving I have to use
entityManager.merge()
because of this post thymeleaf binding collections it is not important. 为了保存,我必须使用
entityManager.merge()
因为此后胸腺叶绑定集合不重要。
First example: 第一个例子:
@Controller
public class EmployeeController extends AbstractCrudController {
// rest of code (...)
@RequestMapping(value = urlFragment + "/create", method = RequestMethod.POST)
public String processNewEmployee(Model model, @ModelAttribute("employee") User employee, BindingResult result, HttpServletRequest request) {
prepareUserForm(model);
if (!result.hasErrors()) {
try {
saveEmployee(employee);
model.addAttribute("success", true);
} catch (Exception e) {
model.addAttribute("error", true);
}
}
return "crud/employee/create";
}
@Transactional
public void saveEmployee(User employee) {
entityManager.merge(employee);
}
private void prepareUserForm(Model model) {
HashSet<Position> positions = new HashSet<Position>(positionRepository.findByEnabledTrueOrderByNameAsc());
HashSet<Role> roles = new HashSet<Role>(roleRepository.findAll());
User employee = new User();
model.addAttribute("employee", employee);
model.addAttribute("allPositions", positions);
model.addAttribute("allRoles", roles);
}
}
This code is throwing TransactionRequiredException, I do not know why? 这段代码抛出TransactionRequiredException,不知道为什么? It looks like @Transactional annotation did not work, so I moved annotation to
processNewEmployee()
看来@Transactional注释无效,因此我将注释移至
processNewEmployee()
Second example: 第二个例子:
@Controller
public class EmployeeController extends AbstractCrudController {
// rest of code (...)
@Transactional
@RequestMapping(value = urlFragment + "/create", method = RequestMethod.POST)
public String processNewEmployee(Model model, @ModelAttribute("employee") User employee, BindingResult result, HttpServletRequest request) {
prepareUserForm(model);
if (!result.hasErrors()) {
try {
entityManager.merge(employee);
model.addAttribute("success", true);
} catch (Exception e) {
model.addAttribute("error", true);
}
}
return "crud/employee/create";
}
private void prepareUserForm(Model model) { /*(.....)*/ }
}
And this code is throwing PersistenceException (because of ConstraintViolationException) and of course I got "Transaction marked as rollbackOnly" exeption. 并且此代码引发PersistenceException(由于ConstraintViolationException),当然我得到了“交易标记为rollbackOnly”示例。
When I try to save email which not exists this code works fine, so I thing that @Transactional annotation is configured well. 当我尝试保存不存在的电子邮件时,此代码可以正常工作,因此我认为@Transactional批注配置得很好。
If this is important I am putting my TransationManagersConfig: 如果这很重要,我要放置我的TransationManagersConfig:
@Configuration
@EnableTransactionManagement
public class TransactionManagersConfig implements TransactionManagementConfigurer {
@Autowired
private EntityManagerFactory emf;
@Autowired
private DataSource dataSource;
@Bean
public PlatformTransactionManager transactionManager() {
JpaTransactionManager tm =
new JpaTransactionManager();
tm.setEntityManagerFactory(emf);
tm.setDataSource(dataSource);
return tm;
}
public PlatformTransactionManager annotationDrivenTransactionManager() {
return transactionManager();
}
}
Could you explain my what I am doing wrong and suggest possible solution of this problem? 您能解释一下我做错了什么,并建议解决此问题的方法吗?
Solution: 解:
Thanks to R4J I have created UserService and in my EmployeeController I am using it instead of entityManager.merge() now it works fine 多亏了R4J,我创建了UserService,并在EmployeeController中使用它代替了EntityManager.merge(),现在可以正常使用了
@Service
public class UserService {
@PersistenceContext
private EntityManager entityManager;
@Transactional
public void merge(User user) {
entityManager.merge(user);
}
}
And EmployeeController: 和EmployeeController:
@Controller
public class EmployeeController extends AbstractCrudController {
@Autowired
private UserService userService;
@RequestMapping(value = urlFragment + "/create", method = RequestMethod.POST)
public String processNewEmployee(Model model, @ModelAttribute("employee") User employee, BindingResult result, HttpServletRequest request) {
// (.....)
userService.merge(employee);
// (.....)
}
}
Your transactions don't work because you call directly 'this.saveEmployee(...)' from your 'public String processNewEmployee' method. 您的交易无效,因为您直接从“公共字符串processNewEmployee”方法中调用“ this.saveEmployee(...)”。
How come? 怎么会?
When you add @Transactional, Spring creates a Proxy for your Component and proxies all public methods. 当添加@Transactional时,Spring为您的组件创建一个代理,并代理所有公共方法。 So when Spring itself calls your method as a HTTP Rest Request it is considered an external call that goes properly through a Proxy and new Transaction is started as required and code works.
因此,当Spring本身将您的方法作为HTTP Rest Request调用时,它被认为是通过代理正确进行的外部调用,并且根据需要启动了新的Transaction,并且代码可以正常工作。
But when you have a Proxied Component and you call 'this.saveEmployee' (that has @Transactional annotation) inside your class code you are actually bypassing the Proxy Spring has created and new Transaction is not started. 但是,当您具有代理组件并在类代码中调用“ this.saveEmployee”(具有@Transactional批注)时,实际上实际上是在绕过已创建的代理Spring,并且不会启动新的Transaction。
Solution: Extract entire database logic to some sort of a Service or DAO and just Autowire it to your Rest Controller. 解决方案:将整个数据库逻辑提取到某种服务或DAO中,然后将其自动连接到Rest Controller。 Then everything should work like a charm.
然后,一切都应该像魅力一样起作用。
You should avoid direct database access from Controllers anyway as it is not a very good practice. 无论如何,您都应避免从Controllers直接访问数据库,因为这不是很好的做法。 Controller should be as thin as possible and contain no business logic because it is just a 'way to access' your system.
控制器应该尽可能的薄,并且不包含任何业务逻辑,因为它只是访问系统的一种方式。 If your entire logic is in the 'domain' then you can add other ways to run business functionalities (like new user creation) in a matter of just few lines of code.
如果您的整个逻辑都在“域”中,那么您只需几行代码就可以添加其他方式来运行业务功能(例如创建新用户)。
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