24. Support InMemory DB

지원하는 인-메모리 데이터베이스  

·        H2 (추천, 콘솔 때문에...)

·        HSQL

·        Derby

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <scope>runtime</scope>
</dependency>
 
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>

  Spring-JDBC가 클래스패스에 있으면 자동 설정이 필요한 빈을 설정 해줍니다.

o   DataSource

o   JdbcTemplate

 

SpringBoot의 @EnableAutoConfiguration 어노테이션에서 2개의 설정을 실행한다.

org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration

---

별도의 설정없이 바로 실행한다면 인-메모리 DB로 실행한다.

설정코드

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Component;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.Statement;
 
@Component
public class H2Runner implements ApplicationRunner {
 
    @Autowired
    JdbcTemplate jdbcTemplate;
 
    @Autowired
    DataSource dataSource;
 
    @Override
    public void run(ApplicationArguments args) throws Exception {
        //try-with-resources를 사용하여 자동 close
        try(Connection connection = dataSource.getConnection()){
            System.out.println(connection.getMetaData().getURL());
            System.out.println(connection.getMetaData().getUserName());
            Statement statement = connection.createStatement();
            String sql = "CREATE TABLE TEST(ID INT PRIMARY KEY, NAME VARCHAR(255));";
            statement.executeUpdate(sql);
        }
 
        String sqlInsert = "INSERT INTO TEST VALUES(1, 'Hello');";
        String sqlInsert2 = "INSERT INTO TEST VALUES(2, 'World');";
        jdbcTemplate.execute(sqlInsert);
        jdbcTemplate.execute(sqlInsert2);
    }
}

테스트 코드

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.test.context.junit4.SpringRunner;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;
import static org.assertj.core.api.Assertions.assertThat;
 
@RunWith(SpringRunner.class)
@SpringBootTest
public class H2RunnerTest {
 
    @Autowired
    JdbcTemplate jdbcTemplate;
 
    @Test
    public void h2Test() throws SQLException {
        String sqlSelect = "SELECT * FROM TEST;";
        List<Map<String, Object>> list =  jdbcTemplate.queryForList(sqlSelect);
        assertThat(list.get(1).get("NAME")).isEqualTo("World");
    }
}

 

H2 콘솔 사용하는 방법

·        spring-boot-devtools를 추가하거나...

·        spring.h2.console.enabled=true 만 추가.

·        /h2-console로 접속 (이 path도 바꿀 수 있음)