在spring boot JPA中,如何正确地将其实体表示具有外键关联的对象POST到另一个实体？

如果我有一个包含另一个类的对象的实体,例如其中包含a的Book实体Publisher如下关联实体:

@ManyToOne
@JoinColumn(name="PUB_CODE", referencedColumnName = "PUB_CODE")
private Publisher pub;

这是一个安全/正确(我在这个例子中看到DB中的正确数据,但不是100%确定它是否适用于所有情况)方法在数据库中发布具有外键关联的对象？我不知道在事务原子性或线程方面是否安全,或者它是否有效.相关代码如下:

Book.java

package app.domain;

/*imports*/

@Entity
public class Book implements Serializable{

    /**
     * 
     */
    private static final long serialVersionUID = -6902184723423514234L;

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

    @Column(nullable = false, unique=true)
    private String bookName;

    @Column(nullable = false)
    private int pageCount;

    @ManyToOne
    @JoinColumn(name="PUB_CODE", referencedColumnName="PUB_CODE")
    private Publisher pub;


    /*public getters and setters*/

}

Publisher.java

package app.domain;

/*imports*/

@Entity
public class Publisher implements Serializable {

    private static final long serialVersionUID = 4750079787174869458L;

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

    @Column(name="PUB_CODE",nullable = false, unique = true)
    private String publisherCode;

    @Column(nullable = false)
    private String publisherName;

    /*public getters and setters*/

}

BookRepo.java

package app.service;

/*imports*/

public interface BookRepo extends JpaRepository{

    @Query("SELECT pb FROM Publisher pb WHERE pb.publisherCode = TRIM(UPPER(:pubCode))")
    public Publisher findPublisherByPubCode(@Param("pubCode")String pubCode);
}

BookController.java

package app.controller;

/*imports*/

@RestController
@RequestMapping(value = "/books")
public class BookController {

    private BookRepo bookRepo;

    @Autowired
    public BookController(BookRepo bookRepo) {
        this.bookRepo = bookRepo;
    }
    //The ApiPathParam is for JSONDOC purposes
    @RequestMapping(value = "/create", method = RequestMethod.POST)
    public List create(@ApiPathParam(name = "book") @RequestBody Book book, @ApiPathParam(name = "pubCode") @RequestParam("pubCode") String pubCode) {
        // Assume exception handling
        Publisher pbToAttachToThisBook = bookRepo.findPublisherByPubCode(pubCode);
        book.setPub(pbToAttachToThisBook);
        bookRepo.save(book);
        return bookRepo.findAll();
    }
}

发布对象主体(输入到POST工具):

{
  "bookName": "goosebumps",
  "id": 0,
  "pageCount": 332,
  "pub": {
    "id": 0,
    "publisherCode": "",
    "publisherName": "",
    "serialVersionUID": 0
  },
  "serialVersionUID": 0
}

提供的pubCode参数输入,也在POST工具中,与上面相同的调用:'SC'

执行上面的代码之后,在Book表中,上面的书中有一个条目,PUB_CODE其外键列已填入'SC',并且List被调用的POST控制器方法的返回显示新添加的书包含Publisher实体发布者的信息(例如全名"Scholastic")PUB_CODE='SC'已存在于数据库中.

谢谢.