@Transaction management internals (Proxy pattern)

How exactly @Transaction works:

Earlier we used to start, close, rollback the transactions programmatically. But with the introduction of @Transaction annotation life became easy. All the underlying transaction management will he handled by the framework.

@Service

public class EmployeeService {

        @Transactional

    public void saveEmployee (Employee employee){

        dao.saveEmployee (employee);

    }

}

The underlying  transaction managers handle the transaction, whichever is used, for example: HibernateTransactionManager or JpaTransactionManager

Internally Spring creates a Proxy for the EmloyeeService class. This proxy class is the one which handles the transaction management related activates, including exception handling and rollback of the transaction

Java interface - Diamond Problem

 public interface InterfaceEx {

    default void name(){} //default method
    static void name6(){}
}

interface InterfaceEx1{
    default void name(){}  // default method
    static void name6(){}
}

//If a class is implementing 2 or more interfaces, with same method signature, compiler enforces class to Override that method.

//This is how diamond problem is resolved.
class ClassEx implements InterfaceEx, InterfaceEx1{   // 

    @Override
    public void name() {

    }
}