How to add custom method to Spring Data JPA

Question

I am looking into Spring Data JPA. Consider the below example where I will get all the crud and finder functionality working by default and if I want to customize a finder t

Answer 1

This is limited in usage, but for simple custom methods you can use default interface methods like:

import demo.database.Customer;
import org.springframework.data.repository.CrudRepository;

public interface CustomerService extends CrudRepository {


    default void addSomeCustomers() {
        Customer[] customers = {
            new Customer("Józef", "Nowak", "nowakJ@o2.pl", 679856885, "Rzeszów", "Podkarpackie", "35-061", "Zamknięta 12"),
            new Customer("Adrian", "Mularczyk", "adii333@wp.pl", 867569344, "Krosno", "Podkarpackie", "32-442", "Hynka 3/16"),
            new Customer("Kazimierz", "Dejna", "sobieski22@weebly.com", 996435876, "Jarosław", "Podkarpackie", "25-122", "Korotyńskiego 11"),
            new Customer("Celina", "Dykiel", "celina.dykiel39@yahoo.org", 947845734, "Żywiec", "Śląskie", "54-333", "Polna 29")
        };

        for (Customer customer : customers) {
            save(customer);
        }
    }
}

EDIT:

In this spring tutorial it is written:

Spring Data JPA also allows you to define other query methods by simply declaring their method signature.

So it is even possible to just declare method like:

Customer findByHobby(Hobby personHobby);

and if object Hobby is a property of Customer then Spring will automatically define method for you.