How to implement Service Layer with Spring?

Question

Does anyone know any tutorial, examples... any source to learn how to implement service layer?

Answer 1

The service layer is where you will have all your business rules before persistence and of course where you will control the database transaction.

//declare aqui a anotação service
@Service
public class MyService {

      ...
}

For transaction control use @Transactional(readonly = true) by default spring already sets up the transaction for only the commit when everything goes right in your method.

You can change this with :

 @Transactional(propagation=Propagation.REQUIRED,readOnly=false) 
    public void save(ProductTech product) { 
        currentSession().save(product); 
        System.out.println(“product saved with sucess”); 
    } 

PROPAGATION_MANDATORY: Requires the use of a transaction, if there is no current transaction, an exception is made.

PROPAGATION_NESTED: Executes within a nested transaction if a current transaction exists.

PROPAGATION_NEVER: Prevents the use of a transaction. If there is a current transaction, an exception is made.

PROPAGATION_NOT_SUPPORTED: Does not use the current transaction. It is always executed without any transaction.

PROPAGATION_REQUIRED: Uses the current transaction if it exists, if it does not exist creates a new transaction.

PROPAGATION_REQUIRES_NEW: Create a new transaction, if a current already exists, suspend it.

PROPAGATION_SUPPORTS: Uses the current transaction if it exists, otherwise executes without transaction.

Ready after that just inject your Service into your Controller