Hibernate interceptors with spring does not intercept - spring

I'm trying to use interceptors with hibernate in order to create a log table.
The application works fine but my interceptors are never triggered when they were supposed to be triggered.
I tried the solutions of this post on stack overflow and I did not succed in making it work.
What I did is:
create an entity class that will be the table where the log are stored (UserLog)
create another class called by the interceptor that will fill my table (dao), in this example it is called UserLogUtil
I tried the first solution, making my interceptor class not dependant on spring #Autowire by making the UserLogUtil a singleton manually and adding the following line to my application.properties : spring.jpa.properties.hibernate.ejb.interceptor=LogInterceptor.
I also tried the second solution by autowiring UserLogUtil however my spring configuration is in xml and although I tried to convert the beans from the above example it did not work.
This is what my interceptor looks like:
public class LogInterceptor extends EmptyInterceptor {
private UserLogUtil userLogUtil = UserLogUtil.getInstance();
public boolean onSave(Object entity,Serializable id, Object[] state,String[] propertyNames,Type[] types)
throws CallbackException {
if (entity instanceof Owner){
userLogUtil.log(........));
}
return false;
}
I think I missed something in the process of building my interceptor and my design could be flawed. Do you have any idea that could make my interceptor function as it should ?

Related

intercept request start and end in Vaadin 14 (Flow) with Spring Boot

I'm using vaadin-spring-boot-starter for integration of Vaadin Framework 14 and Spring Boot.
I would like to override the requestStart and requestEnd methods of the SpringServlet class to do the following things:
put stuff such as the current route / view path and current user ID into the SLF4J MDC in order to include it in each logging statement
log the duration of the request
In Vaadin 8 there was a SpringVaadinServlet class which I could replace by simply annotating my custom subclass with #SpringComponent("vaadinServlet").
This approach no longer works. The vaadin-spring integration contains SpringBootConfiguration which contains a direct call to the SpringServlet constructor:
#Bean
public ServletRegistrationBean<SpringServlet> servletRegistrationBean() {
String mapping = configurationProperties.getUrlMapping();
Map<String, String> initParameters = new HashMap<>();
boolean rootMapping = RootMappedCondition.isRootMapping(mapping);
if (rootMapping) {
mapping = VaadinServletConfiguration.VAADIN_SERVLET_MAPPING;
initParameters.put(Constants.SERVLET_PARAMETER_PUSH_URL,
VaadinMVCWebAppInitializer
.makeContextRelative(mapping.replace("*", "")));
}
ServletRegistrationBean<SpringServlet> registration = new ServletRegistrationBean<>(
new SpringServlet(context, rootMapping), mapping); // <-- HERE
registration.setInitParameters(initParameters);
registration.setAsyncSupported(configurationProperties.isAsyncSupported());
registration.setName(
ClassUtils.getShortNameAsProperty(SpringServlet.class));
return registration;
}
They should use a conditional bean here so we could replace it, but unfortunately they're not.
Just adding a custom ServletRegistrationBean with a copy of the above code (but the constructor call substituted with my own) doesn't work, even with #Primary.
So is there a better way to do what I want than to exclude the whole vaadin-spring autoconfiguration and copy everything in my own configuration bean? It works but I have to check if everything's still OK after each vaadin-spring upgrade.
You could add a VaadinServiceInitListener through which you can add a custom request handler. Alternatively you could use a Filter.

Where to validate uniqueness of field in Spring/Hibernate

I am building a REST API using spring and hibernate. I have come across the issue where I want to create a user and want to know the best practice on how to validate that the user can be created.
My controller has the #Valid annotation on the User object that gets passed into the method, and this checks for valid structure, however there is no #Unique property that gets picked up by #Valid.
I am using the #Column(unique = true) but this throws an error at the persistence level and I feel like that is quite low level and makes it difficult to throw a custom UsernameAlreadyExistsException().
My question here is what is the best practice in terms of preforming this type of validation. I thought about creating a custom annotation but it seems quite messy especially because as the project grows I would need multiple validators for different fields and it also seems to be closley related to tying the service layer to the annotation which seems messy
In my opinion, using custom annotation is the best approach to do stuff like this, you can inject some bean in ConstraintValidator and perform validation. However you can try one of the below unusual approaches, maybe it will fit your requirements.
Spring AOP
Spring Handler Interceptor
JPA Event Listeners
It's just my opinion about this, in most cases I think I will create custom annotations to handle it.
A good practice would be to put validation both on the database (which we know nothing about, but it is not complicated really) and on the Spring's side.
As #kamil-w already said, a good is to write custom constraint validator, see here for an example.
Keep in mind that you can always pass parameters like to constraint annotation, and then access them in your ConstraintValidator, for example.:
#Entity
public class Member {
// ...
#UniqueField(fieldName = "login", context = Member.class)
private String login;
}
#Component
public class UniqueFieldValidator implements ConstraintValidator<UniqueField, Object> {
#PersistenceUnit
private EntityManagerFactory emf;
private Class validationContext;
private String fieldName;
#Override
public void initialize(UniqueField uniqueField) {
this.validationContext = uniqueField.validationContext();
this.fieldName = uniqueField.fieldName();
}
#Override
public boolean isValid(Object value, ConstraintValidatorContext cxt) {
// use value, this.validationContext, this.fieldName and entity manager to check uniqueness
}
}

Spring data rest and business rules validation

I want to seek a best practice for applying business rules when working with spring data rest.
Lets consider following scenario:
I have a Customer and Order in #OneToMany relationship.
I have a business rule saying that Customer needs to have verified flag set to be able to make orders
So I need to make sure that whenever someone POSTs to /orders the Customer making the call is verified.
I'm considering using beforeSave Validators autowiring other service/repositories into the Validator and check whatever needs to be checked.
Is there better way of achieving the same?
There are several ways to solve this. As far as my knowledge goes:
Usage of spring security annotations like #PreAuthorize. The intended use of these annotations is however for security purposes and you are mentioning business rules. I would use these for user authorization rules Spring data rest security chapter
The use of validators as you mentioned yourself. Spring data rest Validators
Use spring data rest events Spring data rest events. You can create global event handlers, however here you need to determine the entity type. I would go with Annotated event handlers to perform business logic Spring data rest annotated event handler
So just for the sake of world piece I'm adding my solution. Went with #2.
The documentation is pretty clear on how to proceed so just sharing few tips which may save you time.
You need to assign validators manually, auto-discovery doesn't work
Manually spelling event type is error prone, some helper Enum could be handy.
Like:
/**
* "beforeSave" gets called on PATCH/PUT methods
* "beforeCreate" on POST
* "beforeDelete" on DELETE
*/
enum Event {
ON_CREATE("beforeCreate"), ON_UPDATE("beforeSave"),
ON_DELETE("beforeDelete");
private String name;
Event(String name) {
this.name = name;
}
}
...
private static void addValidatorForEvents(ValidatingRepositoryEventListener eventListener, Validator validator, Event... events) {
Arrays.asList(events).forEach(event -> eventListener.addValidator(event.name, validator));
}
One out of the box solution you can use to solve your Business rules related problems, is using Spring AOP. What you can do, is define an Annotation (say #X) and place that annotation on top of your POST call.
#Retention(RetentionPolicy.RUNTIME)
#Target(ElementType.METHOD)
public #interface X{}
Next what you need to do is, create an aspect, and run your custom validation logic in this aspect as follows,
#Aspect
#Component
public class CustomAspect {
//You can autowire beans here
#Around("#annotation(qualified name of X)")
public Object customMethod(ProceedingJoinPoint joinPoint) throws Throwable {
flag = customLogic();
if (flag){
return joinPoint.proceed(); //return if logic passes, otherwise
}else{
throw new BusinessRuleException("Business rule violated");
}
}
private boolean customLogic(){
//your custom logic goes here
}
}
And finally apply this annotation on top of any method in controller layer like:
#X
#RequestMapping(method = RequestMethod.POST, value = "do-something")
public void callSomething(HttpServletRequest request) throws Exception {
// your business logic goes here
}
Only thing to note above is that you need to pass HttpServletRequest request explicitly to your controller method in order to AOP aspect get the same context for manipulation of user session related attributes like session_id, etc.
Above solution will help you add business rules on top of your Business Logic and help you with all kinds of pre validations you want to build in your web application. It is a pretty handy application of Spring AOP. Do reach out in case of any

Configuring Spring MockMvc to use custom argument resolver before built-in ones

I have a straightforward test case. I have a controller which has a parameter of a type Spring doesn't support by default, so I wrote a custom resolver.
I create the mock mvc instance I'm using like so:
mvc = MockMvcBuilders.standaloneSetup(controller).setCustomArgumentResolvers(new GoogleOAuthUserResolver()).build();
However, Spring is also registering almost 30 other argument resolvers, one of which is general enough that it is getting used to resolve the argument before mine. How can I set or sort the resolvers so that mine is invoked first?
This worked for me without reflection:
#RequiredArgsConstructor
#Configuration
public class CustomerNumberArgumentResolverRegistration {
private final RequestMappingHandlerAdapter requestMappingHandlerAdapter;
#PostConstruct
public void prioritizeCustomArgumentResolver () {
final List<HandlerMethodArgumentResolver> argumentResolvers = new ArrayList<>(Objects.requireNonNull(requestMappingHandlerAdapter.getArgumentResolvers()));
argumentResolvers.add(0, new CustomerNumberArgumentResolver());
requestMappingHandlerAdapter.setArgumentResolvers(argumentResolvers);
}
}
The issue was that the People class the Google OAuth library I am using extends Map and the mock servlet API provides no way to manipulate the order in which the handlers are registered.
I ended up using reflection to reach into the mocks guts and remove the offending handler.

#transactional in spring jpa not updating table

I am using spring jpa transactions in my project.One Case includes inserting a data in a synchronized method and when another thread accesses it the data is not updated.My code is given below :
public UpdatedDTO parentMethod(){
private UpdatedDTO updatedDTO = getSomeMethod();
childmethod1(inputVal);
return updatedDTO;
}
#Transactional
public synchronized childmethod1(inputVal){
//SomeCodes
//Place where update takes place
TableEntityObject obj = objectRepository.findByInputVal(inputVal);
if(obj == null){
childMethod2(inputVal);
}
}
#Transactional
public void childMethod2(inputVal){
//Code for inserting
TableEntityObject obj = new TableEntityObject();
obj.setName("SomeValue");
obj.setValueSet(inputVal);
objectRepository.save(obj);
}
Now if two threads access at the same time and if first thread completes childmethod2 and childmethod1 and without completing parentMethod() after that if second thread comes to the childMethod1() and checks if data exists,the data is null and is not updated by first thread.I have tried many ways like
#Transactional(propagation = Propagation.REQUIRES_NEW)
public synchronized childmethod1(inputVal){
//SomeCodes
//Place where update takes place
TableEntityObject obj = objectRepository.findByInputVal(inputVal);
if(obj == null){
childMethod2(inputVal);
}
}
#Transactional(propagation = Propagation.REQUIRES_NEW)
public void childMethod2(inputVal){
//Code for inserting
TableEntityObject obj = new TableEntityObject();
obj.setName("SomeValue");
obj.setValueSet(inputVal);
objectRepository.save(obj);
}
also tried taking off #transactional in the childMethod1() but nothing works out.I know im doing something wrong here , but couldnt figure out where and what exactly i am doing wrong.Can anyone help me out with this
#Transactional is resolved using proxies on spring beans. It means it will have no effect if your method with #Transactional is called from the same class. Take a look at Spring #Transaction method call by the method within the same class, does not work?
The easiest would be moving those methods into separate service.
Typical checklist I follow in cases like these :
If Java based configuration then make sure
#EnableTransactionManagement annocation is present in the class
containing the #Configuration annotation
Make sure the transactionManager bean is created, again this should be mentioned in the configuration class.
Use of #Transactional annocatio over the method which is calling the repository, typically a class in the DAO layer
Adding the #Service annotation for the class which is invoking the methods in the repository
Nice blog which explains the Transaction configuration with JPA in depth --> http://www.baeldung.com/2011/12/26/transaction-configuration-with-jpa-and-spring-3-1/68954

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