Spring REST：不能插入具有@manytoone列的行

Question

我正在https://spring.io/guides/gs/accessing-data-rest/中学习spring入门教程

我添加了另一个实体books，它与Person实体有@manytoone关系。Person实体有一个名为bikes的新属性，并且与Bike实体有@OneTomany关系。与入门项目唯一不同的是新属性及其getter和setter：

package hello;

import java.util.List;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToMany;

@Entity
public class Person {

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

    private String firstName;
    private String lastName;

    @OneToMany
    private List<Bike> bikes;

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public List<Bike> getBikes() {
        return bikes;
    }

    public void setBikes(List<Bike> bikes) {
        this.bikes = bikes;
    }
}

实体自行车描述如下：

package hello;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;

@Entity
public class Bike {

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

    private String name;

    @ManyToOne
    @JoinColumn(nullable = false)
    private Person person;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Person getPerson() {
        return person;
    }

    public void setPerson(Person person) {
        this.person = person;
    }
}

package hello;

import java.util.List;

import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.data.rest.core.annotation.RepositoryRestResource;

@RepositoryRestResource(collectionResourceRel = "people", path = "people")
public interface PersonRepository extends PagingAndSortingRepository<Person, Long> {

    List<Person> findByLastName(@Param("name") String name);

}

package hello;

import java.util.List;

import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.data.rest.core.annotation.RepositoryRestResource;

@RepositoryRestResource(collectionResourceRel = "bikes", path = "bikes")
public interface BikeRepository extends PagingAndSortingRepository<Bike, Long> {
    List<Bike> findByName(@Param("name") String name);
}

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 "{  \"name\" : \"Frodos Bike\",  \"person\" : {  \"firstName\" : \"Frodo\",  \"lastName\" : \"Baggins\" } }" http://localhost:8080/bikes

curl -i -X POST -H "Content-Type:application/json" -d "{  \"name\" : \"Frodos Bike\",  \"person_id\" : \"1\" }" http://localhost:8080/bikes

我的问题是：我怎样才能添加一辆新自行车？

Answer 1

您的BikeRepository无法知道哪一行由person：{firstName:“Frodo”,lastName:“Baggins”}表示。您必须告诉您的自行车库如何或在哪里查询它。

试试看

curl-i-x post-h“content-type：application/json”-d“{\”name\“:\frodos bike\”,\“person”：“http://localhost:8080/people/1”}http://localhost:8080/bikes