java - 声明 createEntityManagerFactory 的最佳方式

Question

我实际上是在使用 JPA 开发一个 springboot 项目。我正在寻找更好的实现方式，目前它可以工作，但我的印象是这不是最好的方式

    @RestController
public class inscription {

EntityManagerFactory objFactory = Persistence.createEntityManagerFactory("com.myapplication_jar_0.0.1-SNAPSHOTPU");

 UserJpaController userCtrl = new UserJpaController(objFactory);
 SerialsJpaController licenseCtrl = new SerialsJpaController(objFactory);


   @CrossOrigin(origins = CURRENT_IP)
    @RequestMapping(value = "/createaccount", method = RequestMethod.GET)
    public CreatAccountResponseTemplate createAccount(
            @RequestParam(value = "login") String login,
            @RequestParam(value = "password") String password,
         ) 
    {
        EntityManager manager = objFactory.createEntityManager();

        CreatAccountResponseTemplate responseTemplate = new CreatAccountResponseTemplate();

...}

Answer 1

Spring JPA 有助于减少配置数据存储库所需的样板代码。

也许使用 EntityManagerFactory 作为 RestController 的成员可能是不必要的依赖。这是另一种选择:

1. 创建您的域

实体

@Entity
public class DataCenter {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private String id;

    private String name;

    private String location;

   .......

}

1. 创建接口(interface)存储库以处理与您的实体相关的数据库操作。

存储库

public interface DataCenterRepository extends JpaRepository<DataCenter,String> {}

1. 将 Repository 自动连接到您的 Controller ，此示例适用于标准 Controller ，但它也适用于 RestController。

Controller

@Controller
@RequestMapping("/datacenters")
public class DataCenterController {

    private final DataCenterRepository dataCentersRepository;

    @Autowired
    public DataCenterController(DataCenterRepository dataCentersRepository){
        this.dataCentersRepository=dataCentersRepository;
    }

@RequestMapping(value = "/save", method=RequestMethod.POST)
public ModelAndView  save(@RequestParam(value="name") String datacenterName,
                          @RequestParam(value="age") String datacenterLocation, ModelAndView  modelAndView ) {
    DataCenter dataCenter = new DataCenter(datacenterName, datacenterLocation);
    dataCentersRepository.save(dataCenter);
    modelAndView.addObject("datacenter", dataCenter);
    modelAndView.setViewName("success");
    return modelAndView;
}

    @RequestMapping(value="/all", method=RequestMethod.GET)
    public String getAll(Model model){
        model.addAttribute("datacenters", dataCentersRepository.findAll());
        return "datacenters";
    }

如果你被迫@Autowired你的EntityManagerFactory那么就

@Autowired
private EntityManagerFactory entityManagerFactory;