데이터베이스를 포함한 테스트 시 테스트 격리를 위한 데이터베이스 초기화 코드

DatabaseClean.java

import com.google.common.base.CaseFormat;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.stereotype.Component;

import javax.persistence.Entity;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.transaction.Transactional;
import java.util.List;

import static java.util.stream.Collectors.toList;

@Component
public class DatabaseClean implements InitializingBean {
    @PersistenceContext
    private EntityManager entityManager;

    private List<String> tableNames;

    @Override
    public void afterPropertiesSet() {
        tableNames = entityManager.getMetamodel().getEntities().stream()
                .filter(e -> e.getJavaType().getAnnotation(Entity.class) != null)
                .map(e -> CaseFormat.UPPER_CAMEL.to(CaseFormat.LOWER_UNDERSCORE, e.getName()))
                .collect(toList());
    }

    @Transactional
    public void execute() {
        entityManager.flush();
        entityManager.createNativeQuery("SET REFERENTIAL_INTEGRITY FALSE").executeUpdate();

        for (String tableName : tableNames) {
            entityManager.createNativeQuery(String.format("TRUNCATE TABLE %s", tableName)).executeUpdate();
            entityManager.createNativeQuery(String.format("ALTER TABLE %s ALTER COLUMN ID RESTART WITH 1", tableName)).executeUpdate();
        }

        entityManager.createNativeQuery("SET REFERENTIAL_INTEGRITY TRUE").executeUpdate();
    }
}