Spring HATEOS-如何投射基类型类的所有属性？

Question

给定给定类的投影，有没有办法告诉Spring包含在投影注释类型中定义的类的所有默认属性？

给定2实体类

@Entity 
@Data 
public class Client {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;

    private String nom;
    private String adresseLigne1;
    private String adresseLigne2;
    private String ville;

    @ManyToOne
    private Province province; 
    /* Many other attribute */

}

和

@Entity
@Data
public class Province {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;
    private String name;
}

每个都有一个储存库

@RepositoryRestResource(collectionResourceRel = "Client", path = "Client")
public interface ClientRepository extends PagingAndSortingRepository<Client, Long> {
    List<Client> findBy();
}

-

@RepositoryRestResource(collectionResourceRel = "Province", path = "Province")
public interface ProvinceRepository extends PagingAndSortingRepository<Province, Long> {
    List<Province> findByName(String name);
}

我为客户端获得以下默认json：

{
  "nom" : "Mallowpond High",
  "adresseLigne1" : "895 Gonçal Burg",
  "adresseLigne2" : "Apt. 450",
  "ville" : "Lake Irenehaven",
  "_links" : {
    "self" : {
      "href" : "http://127.0.0.1:8080/api/rest/Client/108"
    },
    "province" : {
      "href" : "http://127.0.0.1:8080/api/rest/Client/108/province"
    }
  }
}

有没有一种方法可以创建一个投影，该投影将返回客户机的所有属性，而不必为客户机中的所有属性编写所有getXXX方法

@Projection(name = "inlineProvince", types = { Client.class })
public interface ClientProjection {
    /* A way to tell the projection to include all of Client attribute */
    Province getProvince();  // This is the linked object I want to add to my json output as an in-line map (i.e have the behaviour as if it did not have it's own Repository)
}

这样我可以在调用时在客户端JSON中嵌入省http://127.0.0.1:8080/api/rest/Client/108?projection=inline:

{
  "nom" : "Mallowpond High",
  "adresseLigne1" : "895 Gonçal Burg",
  "adresseLigne2" : "Apt. 450",
  "ville" : "Lake Irenehaven",
  "_links" : {
    "self" : {
      "href" : "http://127.0.0.1:8080/api/rest/Client/108"
    },
    "province" : {
      "href" : "http://127.0.0.1:8080/api/rest/Client/108/province"
    }
  },
  "province" : {
    "name" : "Quebec"
  }
}

我发现我能做到：

@Projection(name = "inline", types = { Client.class })
public interface ClientProjection {
    @Value("#{target}") 
    Client getClient();
    Province getProvince();  // This is the linked object I want to add to my json output as an in-line map (i.e have the behaviour as if it did not have it's own Repository)
}

但我两个都有客户

{
  "province" : {
    "name" : "quebec"
  },
  "client" : {
      "nom" : "Mallowpond High",
      "adresseLigne1" : "895 Gonçal Burg",
      "adresseLigne2" : "Apt. 450",
      "ville" : "Lake Irenehaven",
      "_links" : {
        "self" : {
          "href" : "http://127.0.0.1:8080/api/rest/Client/108"
        },
        "province" : {
          "href" : "http://127.0.0.1:8080/api/rest/Client/108/province"
        }
      }
  }
}

Answer 1

你的@RestRepositoryResources所产生的内容叫做HAL格式。你所要求的内容偏离了HAL的规范，我建议继续使用标准（原因很明显）。

HAL支持将关系嵌入到资源中。这意味着您将得到一个嵌入的字段，该字段将保存一个包含省的基数1集合。看起来是这样的：

{
  "nom" : "Mallowpond High",
  "adresseLigne1" : "895 Gonçal Burg",
  "adresseLigne2" : "Apt. 450",
  "ville" : "Lake Irenehaven",
  "_links" : {
    "self" : {
      "href" : "http://127.0.0.1:8080/api/rest/Client/108"
    },
    "province" : {
      "href" : "http://127.0.0.1:8080/api/rest/Client/108/province"
    }
  },
  "_embedded"{
     "provinces" : [{
        "name" : "Quebec",
        "_links" : {
          "self" : {
            "href" : "http://127.0.0.1:8080/api/rest/Client/108/province"
          }
        }
     }]
  }
}

不幸的是，Spring的@RepositoryRestResource不容易支持这一点，但仍然相对容易实现。您需要添加一个ResourceAssembler，并将客户端转换为支持_embedded字段的ClientResource。看看这个问题，你如何做到这一点（我自己也用这个）