JPA 설정 방법, Guide To JPA with Springboot

JPA 설정 방법, Guide To JPA with Springboot

 

이전 포스팅에서 JPA를 왜 사용해야 하는지에 대해서 포스팅 했었습니다.

 

Link : aljjabaegi.tistory.com/553

JPA (Java Persistance API) 란? 왜 써야하는가?

 

이제, Springboot Framework에 JPA를 설정하는 방법을 알아보도록 하겠습니다.

 

[Spec]

Springboot 2.3.2

JPA 2.3.2

MariaDB

 

Springboot Project 생성 방법은 아래의 Link를 참고하세요.

 

Link : aljjabaegi.tistory.com/480

Eclipse Spring boot Gradle 프로젝트 간단 생성 방법

gradle project 기반으로 설명을 드리겠습니다. 

Maven을 사용중이라면 pom.xml에 추가하시면 됩니다.

build.gradle 파일을 열어 dependencies 에 JPA, Mariadb-client를 추가해줍니다.

 

/*JPA*/
implementation group: 'org.springframework.boot', name: 'spring-boot-starter-data-jpa', version: '2.3.2.RELEASE'

/*mariadb-java-client*/
compile group: 'org.mariadb.jdbc', name: 'mariadb-java-client', version: '2.6.1'

 

이제 프로젝트 폴더에서 gralde > refresh gradle project를 진행해 주시면 의존성이 주입됩니다.

이제 JPA에 대한 설정 클래스를 생성합니다. 

group pakage > config pakage 내에 PersistanceJPAConfig Class를 생성합니다.

 

import org.springframework.context.annotation.Configuration;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import org.springframework.context.annotation.PropertySource;

@Configuration
@EnableTransactionManagement
@PropertySource("classpath:application.properties")
public class PersistanceJPAConfig {

}

DB 관련 설정을 읽어오기 위해 PropertySource를 src/main/resources/application.properties로 설정했습니다.

 

[참고) application.properties]

spring.datasource.driverClassName=org.mariadb.jdbc.Driver
spring.datasource.url=jdbc:mariadb://127.0.0.1:3306/JPA_TEST
spring.datasource.username=jpaTest
spring.datasource.password=jpaTest

 

Value를 사용해 application.properties 파일의 값을 매핑해 줍니다.

 

import org.springframework.context.annotation.Configuration;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import org.springframework.context.annotation.PropertySource;
import org.springframework.beans.factory.annotation.Value;

@Configuration
@EnableTransactionManagement
@PropertySource("classpath:application.properties")
public class PersistanceJPAConfig {
	
	@Value("${spring.datasource.driverClassName}")
	private String driverClassName;

	@Value("${spring.datasource.url}")
	private String url;
	
	@Value("${spring.datasource.username}")
	private String userName;
	
	@Value("${spring.datasource.password}")
	private String password;
}

 

이제 설정정보를 활용해 DataSource를 Bean에 등록합니다.

 

import org.springframework.context.annotation.Configuration;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import org.springframework.context.annotation.PropertySource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.jdbc.datasource.DriverManagerDataSource;

@Configuration
@EnableTransactionManagement
@PropertySource("classpath:application.properties")
public class PersistanceJPAConfig {
	
	@Value("${spring.datasource.driverClassName}")
	private String driverClassName;

	@Value("${spring.datasource.url}")
	private String url;
	
	@Value("${spring.datasource.username}")
	private String userName;
	
	@Value("${spring.datasource.password}")
	private String password;
    
	@Bean
	public DataSource dataSource(){
	    DriverManagerDataSource dataSource = new DriverManagerDataSource();
	    dataSource.setDriverClassName(driverClassName);
	    dataSource.setUrl(url);
	    dataSource.setUsername(userName);
	    dataSource.setPassword(password);
	    return dataSource;
	}
}

 

설정한 Datasource 설정을 활용해 Entity Manager 와 Transaction, Hibernate 설정 Bean을 추가해줍니다.

 

import org.springframework.context.annotation.Configuration;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import org.springframework.context.annotation.PropertySource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.JpaVendorAdapter;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration
@EnableTransactionManagement
@PropertySource("classpath:application.properties")
public class PersistanceJPAConfig {
	
	@Value("${spring.datasource.driverClassName}")
	private String driverClassName;

	@Value("${spring.datasource.url}")
	private String url;
	
	@Value("${spring.datasource.username}")
	private String userName;
	
	@Value("${spring.datasource.password}")
	private String password;
    
	@Bean
	public DataSource dataSource(){
	    DriverManagerDataSource dataSource = new DriverManagerDataSource();
	    dataSource.setDriverClassName(driverClassName);
	    dataSource.setUrl(url);
	    dataSource.setUsername(userName);
	    dataSource.setPassword(password);
	    return dataSource;
	}
	
	@Bean
	public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
	   LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
	   em.setDataSource(dataSource());
	   em.setPackagesToScan(new String[] {"엔티티 패키지 경로"});
	   JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
	   em.setJpaVendorAdapter(vendorAdapter);
	   em.setJpaProperties(additionalProperties());
	   return em;
	}
	
	@Bean
	public PlatformTransactionManager transactionManager() {
	    JpaTransactionManager transactionManager = new JpaTransactionManager();
	    transactionManager.setEntityManagerFactory(entityManagerFactory().getObject());
	    return transactionManager;
	}

	@Bean
	public PersistenceExceptionTranslationPostProcessor exceptionTranslation(){
	    return new PersistenceExceptionTranslationPostProcessor();
	}

	Properties additionalProperties() {
	    Properties properties = new Properties();
	    properties.setProperty("hibernate.hbm2ddl.auto", "update");
	    properties.setProperty("hibernate.dialect", "org.hibernate.dialect.MySQL5Dialect");
	    return properties;
	}
}

 

Database가 Oracle일 경우 application.properties의 DriverClassName, url 과

additionalProperties 메소드의 hibernate 방언(dialect)만 수정해 주시면 됩니다.

 

[Major DB Dialect]

Oracle(any) : org.hibernate.dialect.OracleDialect

Oracle10g : org.hibernate.dialect.Oracle10gDialect

MySql, MariaDB : org.hibernate.dialect.MySQL5Dialect

MsSql2000 : org.hibernate.dialect.SQLServerDialect 

MsSql2005 : org.hibernate.dialect.SQLServer2005Dialect

MsSql2008 : org.hibernate.dialect.SQLServer2008Dialect

 

[hbm2ddl.auto options]

update : 객체와 스키마 비교, 기존 스키마 유지, 추가/삭제만 진행

create : 시작 시 스키마 삭제, 새로 생성

create-drop : SessionFactory 종료 시 스키마 삭제

 

JPA 관련 설정은 마무리 되었습니다.

다음 포스팅에서 Entity를 생성해 데이터를 조회하는 방법을 알아보도록 하겠습니다.

 

엔티티 매핑 방법

Link : aljjabaegi.tistory.com/562

JPA with Springboot, Entity mapping 데이터 조회 방법