JPA 实体不工作

Question

我的 Spring Person 实体的引导实体不工作。我与 Hobby 实体存在多对多关系，并且 class 正在运行。

不必在 JpaRepository 中定义的预定义函数可以工作，但不能工作。

Class Person

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.Table;
import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;

@Entity
@Table(name = "Person")
public class Person implements Serializable {

    private static final long serialVersionUID = 4582624077512606651L;

    @ManyToMany(fetch = FetchType.LAZY, cascade = {CascadeType.PERSIST, CascadeType.MERGE})
    @JoinTable(name = "person_hobby", joinColumns = {@JoinColumn(name = "person_id")}, inverseJoinColumns = {@JoinColumn(name = "hobby_id")})
    private Set<Hobby> hobby = new HashSet<>();

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

    @Column(name = "firstName")
    private String firstName;

    @Column(name = "lastName")
    private String lastName;

    protected Person() {

    }

    public Person(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    @Override
    public String toString() {
        return String.format("Person[id=%d, firstName='%s', lastName='%s']", id, firstName, lastName);
    }

    public Set<Hobby> getHobby() {
        return hobby;
    }

    public void setHobby(Set<Hobby> hobby) {
        this.hobby = hobby;
    }

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    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 static long getSerialversionuid() {
        return serialVersionUID;
    }

}

Class Hobby

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.ManyToMany;
import javax.persistence.Table;
import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;

@Entity
@Table(name = "Hobby")
public class Hobby implements Serializable {

    private static final long serialVersionUID = 1442665206056041894L;

    @ManyToMany(fetch = FetchType.LAZY, cascade = {CascadeType.PERSIST, CascadeType.MERGE}, mappedBy = "hobby")
    private Set<Person> persons = new HashSet<>();

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

    @Column(name = "title")
    private String title;

    protected Hobby() {

    }

    public Hobby(String title) {
        this.title = title;

    }

    @Override
    public String toString() {
        return "Hobby [persons=" + persons + ", id=" + id + ", title=" + title + "]";
    }

    public Set<Person> getPersons() {
        return persons;
    }

    public void setPersons(Set<Person> persons) {
        this.persons = persons;
    }

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public static long getSerialversionuid() {
        return serialVersionUID;
    }

}

ClassHobbyRepository有工作方法

import ...Hobby;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;

import java.util.List;
import java.util.Set;

public interface HobbyRepository extends JpaRepository<Hobby, Long> {

    public List<Hobby> findByPersons_Id(Long id);

    public List<Hobby> findByPersons_IdIn(Set<Long> ids);

    @Query("select h from Hobby h")
    List<Hobby> findByHobbyHobbyId();

}

但是classPersonRepository有方法不行

import ...Person;
import org.springframework.data.jpa.repository.JpaRepository;

import java.util.List;
import java.util.Set;

public interface PersonRepository  extends JpaRepository<Person, Long> {

    List<Person> findByLastName(String lastName);

    List<Person> findByHobby_Id(Long id);

    List<Person> findByHobby_IdIn(Set<Long> ids);

}

这是有效的调用之一。使用 personService.findByHobby 的相同调用不起作用

    String result = "";
    Set <Long>ids=new HashSet<Long>();
    ids.add(new Long(87));
    ids.add(new Long(90));
    for(Hobby cust : hobbyService.findByPerson_IdIn(ids)){
        result += cust.toString();
    }
    return result;

我尝试过使用各种形式的 JsonBackReference 来构建递归数据库，但都不起作用。如何解决？

更新

这是一些控制台输出。第一行是personService.findAll()有效。

Hibernate: select person0_.id as id1_1_, person0_.first_name as 
    first_na2_1_, person0_.last_name as last_nam3_1_ from person person0_

控制台输出的第二行personService.findByLastName(String name)不起作用。

Hibernate: select person0_.id as id1_1_, person0_.first_name as 
    first_na2_1_, person0_.last_name as last_nam3_1_ from person person0_ where person0_.last_name=?

Table爱好

id(PK)    title          
'88',    'Fotboll',        
'89',    'Film',       
'91',    'Frimärken',       
'92',    'Golf',

Table人

id(PK)    first_name    last_name
'87',    'Adam',        'Johnson'
'90',    'Anna',        'Persson'
'93',    'Nils',        'Svensson'

Table person_hobby

person_id(pk)    hobby_id(pk)      
'87',            '88'
'87',            '89'
'90',            '89'
'90',            '91'
'90',            '92'
'93',            '92'

Answer 1

查看您的 class PersonServiceImpl 第 44 行。您会在其中找到对包含以下行的同一方法的调用：findByHobby_Id。可能通过 class.

实现的接口

修复该行以调用您实际想要调用的内容（我猜是您的存储库？）。

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