In spring boot for jpa java config you need to extend JpaBaseConfiguration and implement it's abstract methods.
@Configuration
public class JpaConfig extends JpaBaseConfiguration {
@Override
protected AbstractJpaVendorAdapter createJpaVendorAdapter() {
final HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
return vendorAdapter;
}
@Override
protected Map<String, Object> getVendorProperties() {
Map<String, Object> properties = new HashMap<>();
properties.put("hibernate.dialect", "org.hibernate.dialect.PostgreSQLDialect");
}
}