Extended Jpa Repository Implementation Base

Whatever project I work on, I always need a project like this. So I’ve been taking the time to implement this code in each project whenever it’s needed. I finally decided to make it an independent project as a Spring Boot starter package. You can use any number of parameters to filter the data. The Criteria.builder() is smart enough to ignore any filter whose value is null.

Usage

Just import dependency. Spring Boot will auto import configuration.

<dependency>
    <groupId>io.github.hurelhuyag</groupId>
    <artifactId>spring-data-jpa-extension</artifactId>
    <version>1.0.1</version>
</dependency>

import io.github.hurelhuyag.jpa.Criteria;
import io.github.hurelhuyag.jpa.Expr;
import io.github.hurelhuyag.jpa.ExtendedJpaRepository;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@EnableJpaRepositories(repositoryBaseClass = ExtendedJpaRepositoryImpl.class)
@SpringBootApplication
class App() {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

interface PersonRepository extends ExtendedJpaRepository<Person, Long> {
}

@Service
@Transactional
@RequiredArgsConstructor
class PersonService {

    private final PersonRepository personRepository;

    // unlike CrudRepository.save(Entity) method, it will directly call EntityManager.persist(Entity)
    void create() {
        personRepository.persist(new Person());
    }

    // Criteria.builder()'s methods will ignore predicate if value is null. So You don't need to check value is null or not
    Page<MyData> findAll(String name, int age, Pageable pageable) {
        return personRepository.findAll(
            Criteria.builder()
                .like("name", name)
                .gte("age", age)
                .build(),
            "Person.withAll", // declare all relation as lazy and use fetch graph to enable join fetch for required attributes
            pageable
        );
    }

    // If you don't like Criteria.builder(), there is another option. But this works differently
    Page<MyData> findAll2(String name, int age, Pageable pageable) {
        return personRepository.findAll(
            List.of(
                new Criteria("name", Expr.EQ, name),
                new Criteria("age", Expr.GTE, age)
            ),
            "Person.withAll", // declare all relation as lazy and use fetch graph to enable join fetch for required attributes
            pageable
        );
    }
}