如何在spring中访问内存数据库

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <version>1.4.200</version>
</dependency>

spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=

@Entity
@Table(name = "user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    private String name;
    private int age;
    
    // 省略getter和setter方法
}

@Repository
public interface UserRepository extends JpaRepository<User, Long> {
    // 可以定义自定义的查询方法
}

@Service
public class UserService {
    @Autowired
    private UserRepository userRepository;
    
    public List<User> getAllUsers() {
        return userRepository.findAll();
    }
    
    public User getUserById(Long id) {
        return userRepository.findById(id).orElse(null);
    }
    
    public User saveUser(User user) {
        return userRepository.save(user);
    }
    
    public void deleteUser(Long id) {
        userRepository.deleteById(id);
    }
}