Adding business logic to a spring-data-rest application

There are many possibilities.

1. Validators (http://docs.spring.io/spring-data/rest/docs/current/reference/html/#validation) for validating received objects.

2. Event Handlers http://docs.spring.io/spring-data/rest/docs/current/reference/html/#events) that will be called when validation was okay.

3. Custom Controllers (http://docs.spring.io/spring-data/rest/docs/current/reference/html/#customizing-sdr.overriding-sdr-response-handlers) when you manually want to handle the request.

I ended up creating a custom Aspect that's around repository method. Something like this (groovy):

@Aspect
@Component
@Slf4j
class AccountServiceAspect {

@Around("execution(* com.test.accounts.account.repository.AccountRepository.save*(..))")
    Object saveAccount(ProceedingJoinPoint jp) throws Throwable {
        log.info("in aspect!")
        Object[] args = jp.getArgs()

        if (args.length <= 0 || !(args[0] instanceof Account))
            return jp.proceed()

        Account account = args[0] as Account

        account.active = true
        jp.proceed(account)
    }
}

Not ideal but you can modify model before saving it without writing spring data rest controllers from scratch.

A good answer at : https://www.reddit.com/r/java/comments/90wk5y/spring_rest_business_logic/

If your future service might have any of business logic, even simple, you should not use Spring Data Rest.

Spring Data Rest is perfectly suits case when you only need basic control of entities(think CRUD).

With the case one could start with spring web, rest controllers and use JSON representation as your views.

The Events and Validator can help if your logic deals with One entity.

Don't get me wrong, in a normal project you can find many places which there are not heavy logic and the Spring Data Rest fits quit well and can save lots of time.

I guess you are talking about the 3 tier architecture business tier, presentation tier and persistence tier.

I usually follow this to group my code together presentation tier will be the one that has all the classes [@RestController] Rest annotations and methods that is directly interacting with the post and get calls by the front end .

These classes will in turn Autowire the business tier and Service tier for getting data from the database or adding some business logic before fetching from the database.

Even ou can make use of RepositoryRestController . To take advantage of Spring Data REST’s settings, message converters, exception handling, and more,

Hope this is what you were looking at.