Spring data rest和jpa@OneTomany重复“_links”

Question

下面是我的spring-data-rest存储库：

public interface ProfileJpaRepository extends JpaRepository<Profile, Long> {
}

下面是我的实体（为简洁起见，没有显示getter和setter）。

profile.java：

@Entity
@Table(name = "PROFILE")
public class Profile {

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

    private String description;

    // Don't use mappedBy="profile" because attributes are not persisted properly
    @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, orphanRemoval = true)
    @JoinColumn(name = "PROFILE_ID")
    private Set<Attribute> attributes;

    ...
}

@Entity
@Table(name = "ATTRIBUTE")
public class Attribute {

     @Id
     @GeneratedValue(strategy=GenerationType.AUTO)
     @Column(name = "ID")
     private Long id;

     private String uri;

     @ManyToOne(fetch = FetchType.EAGER)
     private Profile profile;

     @ElementCollection(fetch = FetchType.EAGER)
     @CollectionTable(name="ATTRIBUTE_DATAS")
     private List<String> datas = new ArrayList<>();

     public Attribute() {}

     public Attribute(String uri, List<String> datas) {
        this.uri = uri;
        this.datas = datas;
    }

    ...
}

{
    "description" : "description-value",
    "attributes" : [
        {
            "uri" : "uri-a",
            "datas" : ["uri-a-value"]
        },
        {
            "uri" : "uri-b",
            "datas" : ["uri-b-value"]
        }
    ]
}

{
  "_embedded" : {
    "profiles" : [ {
      "description" : "description-value",
      "attributes" : [ {
        "uri" : "uri-a",
        "datas" : [ "uri-a-value" ],
        "_links" : {
          "profile" : {
            "href" : "http://localhost:8880/profiles/1"
          }
        }
      }, {
        "uri" : "uri-b",
        "datas" : [ "uri-b-value" ],
        "_links" : {
          "profile" : {
            "href" : "http://localhost:8880/profiles/1"
          }
        }
      } ],
      "_links" : {
        "self" : {
          "href" : "http://localhost:8880/profiles/1"
        },
        "profile" : {
          "href" : "http://localhost:8880/profiles/1"
        }
      }
    } ]
  },
  "_links" : {
    "self" : {
      "href" : "http://localhost:8880/profiles"
    },
    "profile" : {
      "href" : "http://localhost:8880/profile/profiles"
    }
  },
  "page" : {
    "size" : 20,
    "totalElements" : 1,
    "totalPages" : 1,
    "number" : 0
  }
}

{
  "_embedded" : {
    "profiles" : [ {
      "description" : "description-value",
      "attributes" : [ {
        "uri" : "uri-a",
        "datas" : [ "uri-a-value" ]
      }, {
        "uri" : "uri-b",
        "datas" : [ "uri-b-value" ]
      } ],
      "_links" : {
        "self" : {
          "href" : "http://localhost:8880/profiles/1"
        },
        "profile" : {
          "href" : "http://localhost:8880/profiles/1"
        }
      }
    } ]
  },
  "_links" : {
    "self" : {
      "href" : "http://localhost:8880/profiles"
    },
    "profile" : {
      "href" : "http://localhost:8880/profile/profiles"
    }
  },
  "page" : {
    "size" : 20,
    "totalElements" : 1,
    "totalPages" : 1,
    "number" : 0
  }
}

有关依赖关系版本的更多信息可以在这里找到。如果需要，我没有重写这些(http://docs.spring.io/spring-boot/docs/1.4.4.release/reference/html/appendience-dependency-versions.html)

多谢了。

Answer 1

为了解决这个问题，我一直在使用投影（更多信息见http://docs.spring.io/spring-data/rest/docs/current/reference/html/#projections-excerpts)。我在发帖的时候并没有意识到这个特点。

我必须注释我的存储库并告诉它使用我的InlineAttributes投影：

import org.springframework.data.rest.core.annotation.RepositoryRestResource;

@RepositoryRestResource(excerptProjection = InlineAttributes.class)
public interface ProfileJpaRepository extends JpaRepository<Profile, Long> {
}

在Attribute类上，我必须添加@jsonIgnore注释：

import com.fasterxml.jackson.annotation.JsonIgnore;

@Entity
@Table(name = "ATTRIBUTE")
public class Attribute {
     ...

     @ManyToOne(fetch = FetchType.EAGER)
     @JsonIgnore
     private Profile profile;

     ...
}

import org.springframework.data.rest.core.config.Projection;
import com.fasterxml.jackson.annotation.JsonPropertyOrder;    

@Projection(name = "inlineAttributes", types = { Profile.class })
@JsonPropertyOrder({ "description", "attributes" })
public interface InlineAttributes {

    public String getDescription();
    public Set<Attribute> getAttributes();
}

http://localhost:8880/profiles?projection=inlineAttributes