spring-boot에서 h2 사용

sample-spring-boot-h2

build.gradle

    implementation('org.springframework.boot:spring-boot-starter-data-jpa')
    runtimeOnly('org.springframework.boot:spring-boot-devtools')
    implementation('com.h2database:h2')
    testImplementation('org.springframework.boot:spring-boot-starter-test')

아래 파일에 영속화됨

/src/main/resources/db/testdb

application.properties

spring.datasource.driver-class-name=org.h2.Driver
# [H2 Console] JDBC URL: jdbc:h2:C:\Users\aya-win10\engineering\projects\java\spring-boot\sample-spring-boot-h2\src\main\resources\db\testdb
# persistent database
spring.datasource.url=jdbc:h2:./src/main/resources/db/testdb;DB_CLOSE_ON_EXIT=TRUE;MODE=MySQL
spring.datasource.username=sa
spring.datasource.password=
spring.h2.console.enabled=false

Customer.java

@Entity
public class Customer {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Long id;
    private String firstName;
    private String lastName;

    protected Customer() {}

    public Customer(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    @Override
    public String toString() {
        return String.format(
                "Customer[id=%d, firstName='%s', lastName='%s']",
                id, firstName, lastName);
    }

}

CustomerRepository

public interface CustomerRepository extends CrudRepository<Customer, Long> {

    List<Customer> findByLastName(String lastName);
}

응용

@SpringBootApplication
public class Application {
    private static final Logger log = LoggerFactory.getLogger(Application.class);

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }


    @Bean
    public CommandLineRunner demo(CustomerRepository repository) {
        return (args) -> {
            // save a couple of customers
            repository.save(new Customer("Jack", "Bauer"));
            repository.save(new Customer("Chloe", "O'Brian"));
            repository.save(new Customer("Kim", "Bauer"));
            repository.save(new Customer("David", "Palmer"));
            repository.save(new Customer("Michelle", "Dessler"));

            // fetch all customers
            log.info("Customers found with findAll():");
            log.info("-------------------------------");
            for (Customer customer : repository.findAll()) {
                log.info(customer.toString());
            }
            log.info("");

            // fetch an individual customer by ID
            repository.findById(1L)
                .ifPresent(customer -> {
                    log.info("Customer found with findById(1L):");
                    log.info("--------------------------------");
                    log.info(customer.toString());
                    log.info("");
                });

            // fetch customers by last name
            log.info("Customer found with findByLastName('Bauer'):");
            log.info("--------------------------------------------");
            repository.findByLastName("Bauer").forEach(bauer -> {
                log.info(bauer.toString());
            });
            // for (Customer bauer : repository.findByLastName("Bauer")) {
            //  log.info(bauer.toString());
            // }
            log.info("");
        };
    }
}