I'm looking at some existing code and wanted to know what happen's in the following scenario with Spring's #Transactional annotation? Consider the following example:
A POST request hits a #Controller annotated with #Transactional:
#ResponseBody
#Transactional
#RequestMapping(value="/send", method=RequestMethod.POST)
public void send(#RequestBody Response response) {
try {
DBItem updatedDbItem = repository.updateResponse(response);
if (updatedDbItem == null){
//some logging
}
} catch(Exception ex) {
//some logging
}
}
The controller calls a non #transactional repository method which sets a value and in turns calls a another #Transactional method:
#Override
public DBItem updateResponse(Response response) {
try {
DBItem dBItem = findResponseById(response.getKey());
if (dBItem != null){
dBItem.setSomeField(response.getValue());
return updateDataBaseItem(response);
}
} catch (Exception ex) {
//some logging
}
return null;
}
The following updateDataBaseItem() method is common and called from other non transactional methods as well as the above method:
#Transactional
#Override
public DBItem updateDataBaseItem(Response response){
try {
DBItem dBItem = em.merge(response);
return dBItem;
} catch (Exception ex) {
//some logging
}
return null;
}
send() => spring detect #transaction with default parameters
actually Propagation setting is REQUIRED and the spring join the exist transaction or create new if none.
repository.updateResponse(..) => No transactions params the method execute within the same transaction already exist
updateDataBaseItem(..) => calling the method in same repository , spring will not recognize the #Transaction annotation because the use of proxy mode, so this method will be executed within the same transaction
a method within the target object calling another method of the target
object, will not lead to an actual transaction at runtime even if the
invoked method is marked with #Transactional
Related
I am new to String, SpringBoot.
Can we suppress thrown exception in a method annotated with #AfterThrowing?
I mean when an exception is thrown, it will suppress that and will return a default value on behalf of the invoking method?
Say, I have a controller -
#RestController
public class MyRestController implements IRestController{
#Override
#GetMapping("hello-throw")
public String mustThrowException(#RequestParam(value = "name")final String name) throws RuntimeException {
System.out.println("---> mustThrowException");
if("Bakasur".equals(name)) {
throw new RuntimeException("You are not welcome here!");
}
return name + " : Welcome to the club!!!";
}
}
I have created a #AspectJ, as follows -
#Aspect
#Component
public class MyAspect {
#Pointcut("execution(* com.crsardar.handson.java.springboot.controller.IRestController.*(..))")
public void executionPointcut(){
}
#AfterThrowing(pointcut="executionPointcut()",
throwing="th")
public String afterThrowing(JoinPoint joinPoint, Throwable th){
System.out.println("\n\n\tMyAspect : afterThrowing \n\n");
return "Exception handeled on behalf of you!";
}
}
If I run this & hit a ULR like - http://localhost:8080/hello-throw?name=Bakasur
I will get RuntimeException, but, I want to return a default message like - Exception handeled on behalf of you!, can we do it using #AfterThrowing?
I know it can be done using #Around, but around will be called on every hit of the url, that I do not want
What you want to do is Exception Handling on the controller. You don't need to build it yourself, Spring already supports you with some annotations like #ExceptionHandler and #ControllerAdvice. Best would be to follow this example: https://spring.io/blog/2013/11/01/exception-handling-in-spring-mvc#using-controlleradvice-classes
#ControllerAdvice
class GlobalControllerExceptionHandler {
#ResponseStatus(HttpStatus.CONFLICT) // 409
#ExceptionHandler(DataIntegrityViolationException.class)
public void handleConflict() {
// Nothing to do
}
}
#ControllerAdvice
class GlobalDefaultExceptionHandler {
public static final String DEFAULT_ERROR_VIEW = "error";
#ExceptionHandler(value = Exception.class)
public ModelAndView
defaultErrorHandler(HttpServletRequest req, Exception e) throws Exception {
// If the exception is annotated with #ResponseStatus rethrow it and let
// the framework handle it - like the OrderNotFoundException example
// at the start of this post.
// AnnotationUtils is a Spring Framework utility class.
if (AnnotationUtils.findAnnotation
(e.getClass(), ResponseStatus.class) != null)
throw e;
// Otherwise setup and send the user to a default error-view.
ModelAndView mav = new ModelAndView();
mav.addObject("exception", e);
mav.addObject("url", req.getRequestURL());
mav.setViewName(DEFAULT_ERROR_VIEW);
return mav;
}
}
You should use the fully qualified name of the class before method's name when you're referring to a pointcut. So, you should change #AfterThrowing something like this.
#AfterThrowing(pointcut="packageName.MyAspect.executionPointcut()",
throwing="th")
Please note that packageName is full package name of MyAspect.
I try save list of entities to Oracle Db.
#Transactional
public void save() {
//logick
for (QuittanceType quittanceType : quittance) {
quittancesService.parseQuittance(quittanceType);
}
//logick
}
On each step I call this method:
#Transactional
#Override
public void parseQuittance(QuittanceType quittance) {
try {
//logick create payToChargeDb
paymentToChargeService.saveAndFlush(payToChargeDb);
} catch (Exception e) {
log.warn("Ignore.", e);
}
}
and method
#Override
public PaymentsToCharge saveAndFlushIn(PaymentsToCharge paymentsToCharge) {
return paymentToChargeRepository.saveAndFlush(paymentsToCharge);
}
When I try save entity with constraint My main transaction rollback and I get stacktrace:
Caused by: java.sql.BatchUpdateException: ORA-02290: CHECK integrity constraint violated(MYDB.PAYMENTS_TO_CHARGE_CHK1)
But I want skip not success entities and save success. I marck my method
#Transactional(propagation = Propagation.REQUIRES_NEW)
and it look like this:
#Transactional
#Override
public void parseQuittance(QuittanceType quittance) {
try {
//logick create payToChargeDb
paymentToChargeService.saveAndFlushInNewTransaction(payToChargeDb);
} catch (Exception e) {
log.warn("Ignore.", e);
}
}
and
#Transactional(propagation = Propagation.REQUIRES_NEW)
#Override
public PaymentsToCharge saveAndFlushInNewTransaction(PaymentsToCharge paymentsToCharge) {
return paymentToChargeRepository.saveAndFlush(paymentsToCharge);
}
But when I try save entity with constraint I not get exception and not enter to catcj block. just stop working debugging and the application continues to work. I do not get any errors. and as if rollback is happening
The proxy created by #Transactional does not intercept calls within the object.
In proxy mode (which is the default), only external method calls
coming in through the proxy are intercepted. This means that
self-invocation (in effect, a method within the target object calling
another method of the target object) does not lead to an actual
transaction at runtime even if the invoked method is marked with
#Transactional. Also, the proxy must be fully initialized to provide
the expected behavior, so you should not rely on this feature in your
initialization code (that is, #PostConstruct).
https://docs.spring.io/spring/docs/current/spring-framework-reference/data-access.html#transaction-declarative
The same documentation recommends use of AspectJ if you want this behaviour.
I am new to Spring AOP. I need to execute methods only if the user is authorized.
Here's my code.
#Before("some pointcut")
public HttpStatus checkUserAuthentication(String userName)
{
if( userAuthorized(userName) )
{
//go on executing method
} else {
return HttpStatus.FORBIDDEN;
}
}
Is there any alternative for ProceedingJoinPoint.proceed when using JoinPoint or can I use ProceedingJoinPoint with #Before advice? How to proceed with executing the if statement if the user is authorized.
I solved this using #Around advice. and changing the return type to Object so that it can return ProceedingJoinPoint on successfull verification.
#Around("some pointcut")
public Object checkUserAuthentication(ProceedingJoinPoint pjp, String userName)
{
if( userAuthorized(userName) )
{
return pjp.roceed();
} else {
return new ResponseEntity<>(HttpStatus.FORBIDDEN);
}
}
using #Around as advice the control can be passed to the method after verification.
I have the following RESTful Services method :
#PostMapping("/ajouterNewField")
public String ajouterField(#Valid #ModelAttribute("field") Fields field, Model model) throws IOException {
fieldDao.save(field);
// SOME CODE
return displayListeChamps( model);
}
The method is working fine and my question is how to handle any error (database not connected ...) or every issue that can happen durring the execution of this RESTful Services method.
You can use #ControllerAdvice
Refer to the code below
#ControllerAdvice
public String NyExceptionHandlerAdvice {
private final Logger logger = ...;
#ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
#ExceptionHandler({MyRunTimeException.class})
public void handleMyRunTimeException(Exception e) {
logger.error("Exception : ", e);
}
return MY_ERROR_STRING;
}
Best Practice is:
You can have your code throw RunTimeExceptions and handle all of them together or separately in handler methods similar to handleMyRunTimeException above.
You can decide what status code your request should return upon exception.
Basically you'll have to a sort of exception handler for any kind of exception your method might throw:
public class FooController{
// ...
#ExceptionHandler({ CustomException1.class, CustomException2.class })
public void handleException() {
//
}
}
Here's a nice article about that: https://www.baeldung.com/exception-handling-for-rest-with-spring
When I go to /confirmation-account link, in tomcat console I can see that if and else block is also executed. I can see:
print from ColorConsoleHelper.getGreenLog("loginView") and from ColorConsoleHelper.getGreenLog("confirmationAccountView")
This is really strange behavior. Why?
#RequestMapping(value = "/confirmation-account", method = RequestMethod.GET)
#Transactional
public ModelAndView displayConfirmationAccountPage(ModelAndView modelAndView, #RequestParam Map<String, String> requestParams) {
final int ACTIVE_USER = 1;
// find the user associated with the confirmation token
UserEntity userEntity = userService.findUserByConfirmationToken(requestParams.get("token"));
// this should always be non-null but we check just in case
if (userEntity!=null) {
// set the confirmation token to null so it cannot be used again
userEntity.setConfirmationToken(null);
// set enabled user
userEntity.setEnabled(ACTIVE_USER);
// save data: (token to null and active user)
saveAll(userEntity.getTrainings());
/*
RedirectAttributes won't work with ModelAndView but returning a string from the redirecting handler method works.
*/
modelAndView.addObject("successMessage", "Konto zostało pomyślnie aktywowane!");
modelAndView.setViewName("loginView");
ColorConsoleHelper.getGreenLog("loginView");
} else {
ColorConsoleHelper.getGreenLog("confirmationAccountView");
modelAndView.addObject("errorMessage", "Link jest nieprawidłowy...");
modelAndView.setViewName("confirmationAccountView");
}
return modelAndView;
}
public void saveAll(List<TrainingUserEntity> trainingUserEntityList) {
for ( TrainingUserEntity trainingUserEntity : trainingUserEntityList) {
entityManagerService.mergeUsingPersistenceUnitB(trainingUserEntity);
}
}
public void mergeUsingPersistenceUnitB(Object object) {
EntityManager entityManager = getEntityManagerPersistenceUnitB();
EntityTransaction tx = null;
try {
tx = entityManager.getTransaction();
tx.begin();
entityManager.merge(object);
tx.commit();
}
catch (RuntimeException e) {
if ( tx != null && tx.isActive() ) tx.rollback();
throw e; // or display error message
}
finally {
entityManager.close();
}
}
Below solution & explanation:
Because of /confirmation-account link is invoke twice, what is caused by dynamic proxy and #Transactional method annotated in controller It is mandatory to check how many displayConfirmationAccountPage method is invoked. It is workaround.
What do you think it is good or not to annotated #Transactional controller method?