我想知道在应用程序启动之前加载初始数据库数据的最佳方法是什么?我要找的是一些东西,将填补我的H2数据库与数据。
例如,我有一个域模型“User”,我可以通过访问/users访问用户,但最初在数据库中不会有任何用户,所以我必须创建它们。有没有办法自动用数据填充数据库?
目前,我有一个Bean,它由容器实例化并为我创建用户。
例子:
@Component
public class DataLoader {
private UserRepository userRepository;
@Autowired
public DataLoader(UserRepository userRepository) {
this.userRepository = userRepository;
LoadUsers();
}
private void LoadUsers() {
userRepository.save(new User("lala", "lala", "lala"));
}
}
但我非常怀疑这是不是最好的办法。真的是这样吗?
最紧凑的(对于动态数据)将@mathias-dpunkt解决方案放入MainApp(使用Lombok @AllArgsConstructor):
@SpringBootApplication
@AllArgsConstructor
public class RestaurantVotingApplication implements ApplicationRunner {
private final VoteRepository voteRepository;
private final UserRepository userRepository;
public static void main(String[] args) {
SpringApplication.run(RestaurantVotingApplication.class, args);
}
@Override
public void run(ApplicationArguments args) {
voteRepository.save(new Vote(userRepository.getOne(1), LocalDate.now(), LocalTime.now()));
}
}
有多种方法可以实现这一点。我倾向于使用以下选项之一:
选项1:使用CommandLineRunner bean初始化:
@Bean
public CommandLineRunner loadData(CustomerRepository repository) {
return (args) -> {
// save a couple of customers
repository.save(new Customer("Jack", "Bauer"));
repository.save(new Customer("Chloe", "O'Brian"));
repository.save(new Customer("Kim", "Bauer"));
repository.save(new Customer("David", "Palmer"));
repository.save(new Customer("Michelle", "Dessler"));
// fetch all customers
log.info("Customers found with findAll():");
log.info("-------------------------------");
for (Customer customer : repository.findAll()) {
log.info(customer.toString());
}
log.info("");
// fetch an individual customer by ID
Customer customer = repository.findOne(1L);
log.info("Customer found with findOne(1L):");
log.info("--------------------------------");
log.info(customer.toString());
log.info("");
// fetch customers by last name
log.info("Customer found with findByLastNameStartsWithIgnoreCase('Bauer'):");
log.info("--------------------------------------------");
for (Customer bauer : repository
.findByLastNameStartsWithIgnoreCase("Bauer")) {
log.info(bauer.toString());
}
log.info("");
}
}
选项2:使用模式和数据SQL脚本进行初始化
先决条件:
application.properties
spring.jpa.hibernate.ddl-auto=none
解释:
没有ddl-auto SQL脚本将被忽略
休眠和触发默认行为-扫描项目
@实体和/或@表注释类。
然后,在你的MyApplication类中粘贴这个:
@Bean(name = "dataSource")
public DriverManagerDataSource dataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName("org.h2.Driver");
dataSource.setUrl("jdbc:h2:~/myDB;MV_STORE=false");
dataSource.setUsername("sa");
dataSource.setPassword("");
// schema init
Resource initSchema = new ClassPathResource("scripts/schema-h2.sql");
Resource initData = new ClassPathResource("scripts/data-h2.sql");
DatabasePopulator databasePopulator = new ResourceDatabasePopulator(initSchema, initData);
DatabasePopulatorUtils.execute(databasePopulator, dataSource);
return dataSource;
}
脚本文件夹位于资源文件夹下(IntelliJ Idea)
希望它能帮助到别人
更新04-2021:这两个选项都很适合与Spring Profiles结合使用,因为这将帮助您避免创建额外的配置文件,使您作为开发人员的生活变得轻松。