Question

我正在尝试创建一个抽象类来执行所需的常见REST操作，但如果我正在尝试做的事情是可能的话，则无法解决。我已经尝试了很多方法，但是已经将下面的代码剥夺了它应该如何在我脑海中起作用

根据以下建议更新课程。现在的问题是具体类中的构造函数是无效的，因为CustomerRepository不能分配给JpaRepository，尽管它扩展了该接口。

AbstractRestController

public abstract class AbstractRestController<T> {

  private final JpaRepository<T, Serializable> repository;

  public AbstractRestController(JpaRepository<T, Serializable> repository) {
    this.repository = repository;
  }

  @RequestMapping(value = "/{id}", method = RequestMethod.GET)
  public ResponseEntity<JsonResponseBody<T>> getOne(@PathVariable Long id) {
    T restObj = repository.findOne(id);
    JsonResponseBody<T> response = new JsonResponseBody<>(ResponseStatus.SUCCESS, restObj);
    return ResponseEntity.ok().contentType(MediaType.APPLICATION_JSON_UTF8).body(response);
  }

  protected JpaRepository<T, Serializable> getRepository() {
    return repository;
  }
}

CustomerController

@RestController
@RequestMapping(value = "/api/v1/customer")
public class CustomerController extends AbstractRestController<Customer> {

    @Autowired
    public CustomerController(CustomerRepository repository){
        super(repository);
    } 
}

CustomerRepository

public interface CustomerRepository extends JpaRepository<Customer, Long> {

}

Answer 1

实际上，正如@ dino-tw所提到的，您正在尝试实例化具有未定义依赖关系的抽象类。您绝对可以拥有一个抽象控制器类，甚至可以定义将由所有子类继承的请求处理方法。试试这个：

public abstract class AbstractRestController<T, ID extends Serializable> {

    private final JpaRepository<T, ID> repository;  

    public AbstractRestController(JpaRepository<T, ID> repository){
        this.repository = repository;
    }

    @RequestMapping(value = "/{id}", method = RequestMethod.GET)
    public ResponseEntity<JsonResponseBody<T>> getOne(@PathVariable ID id) {
        T restObj = repository.findOne(id);
        JsonResponseBody<T> response = new JsonResponseBody<>(ResponseStatus.SUCCESS, restObj);      
        return ResponseEntity.ok().contentType(MediaType.APPLICATION_JSON_UTF8).body(response);
    }

    protected JpaRepository<T, ID> getRepository(){ return repository; }
}


@RestController
@RequestMapping(value = "/api/v1/customer")
public class CustomerController extends AbstractRestController<Customer, Long> {

    @Autowired
    public CustomerController(CustomerRepository repository){
        super(repository);
    }  

}

抽象类中的Spring Autowired Repository

1 个答案: