java - Spring JPA REST 一对多

Question

我想扩展示例 Accessing JPA Data with REST通过将地址列表添加到 Person 实体。所以，我添加了一个带有 @OneToMany 注释的 addresses 列表:

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

    private String firstName;
    private String lastName;

    @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    private List<Address> addresses = new ArrayList<>();

   // get and set methods...
}

Address 类非常简单:

@Entity
public class Address {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;
    private String street;
    private String number;
    // get and set methods...
}

最后我添加了 AddressRepository 接口(interface):

public interface AddressRepository extends PagingAndSortingRepository<Address, Long> {}

然后我尝试用一​​些地址发布一个人:

curl -i -X POST -H "Content-Type:application/json" -d '{  "firstName" : "Frodo",  "lastName" : "Baggins", "addresses": [{"street": "somewhere", "number": 1},{"street": "anywhere", "number": 0}]}' http://localhost:8080/people

我得到的错误是:

Could not read document: Failed to convert from type [java.net.URI] to type [ws.model.Address] for value 'street';
nested exception is java.lang.IllegalArgumentException: Cannot resolve URI street. Is it local or remote? Only local URIs are resolvable. (through reference chain: ws.model.Person[\"addresses\"]->java.util.ArrayList[1]);
nested exception is com.fasterxml.jackson.databind.JsonMappingException: Failed to convert from type [java.net.URI] to type [ws.model.Address] for value 'street'; nested exception is java.lang.IllegalArgumentException: Cannot resolve URI street. Is it local or remote? Only local URIs are resolvable. (through reference chain: ws.model.Person[\"addresses\"]->java.util.ArrayList[1])

创建一对多和多对多关系并向它们发送 json 对象的正确方法是什么？

Answer 1

您应该先 POST 这两个地址，然后在您的个人 POST 中使用返回的 URL(例如 http://localhost:8080/addresses/1 和 http://localhost:8080/addresses/2):

curl -i -X POST -H "Content-Type:application/json" -d '{  "firstName" : "Frodo",  "lastName" : "Baggins", "addresses": ["http://localhost:8080/addresses/1","http://localhost:8080/addresses/2"]}' http://localhost:8080/people

如果你想先保存这个人然后添加它的地址你可以这样做:

curl -i -X POST -H "Content-Type:application/json" -d '{  "firstName" : "Frodo",  "lastName" : "Baggins"}' http://localhost:8080/people
curl -i -X POST -H "Content-Type:application/json" -d '{"street": "somewhere", "number": 1}' http://localhost:8080/addresses
curl -i -X POST -H "Content-Type:application/json" -d '{"street": "anywhere", "number": 0}' http://localhost:8080/addresses
curl -i -X PATCH -H "Content-Type: text/uri-list" -d "http://localhost:8080/addresses/1
http://localhost:8080/addresses/2" http://localhost:8080/people/1/addresses