在应用程序启动时获取mappedBy引用未知目标实体属性异常

Question

我有两个实体，其中一个我正在使用一个用户输入的PK。

我在启动springboot应用程序时遇到以下异常。

我的实体类如下所示。

import java.util.HashSet;
import java.util.Set;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.persistence.Table;

@Entity
@Table(name="EMPLOYEE")
public class Employee {

    @Id
    @Column(name="NAME")
    private String name;

    @Column(name="PHONE_NUMBER")
    private String phoneNumber;

    @OneToMany(mappedBy = "employee")
    private Set<Department> departments = new HashSet<Department>();

    public Employee(String name, String phoneNumber, Set<Department> department) {
        super();
        this.name = name;
        this.phoneNumber = phoneNumber;
        this.departments = department;
    }

    public String getName() {
        return name;
    }

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

    public String getPhoneNumber() {
        return phoneNumber;
    }

    public void setPhoneNumber(String phoneNumber) {
        this.phoneNumber = phoneNumber;
    }

    public Set<Department> getDepartment() {
        return departments;
    }

    public void setDepartment(Set<Department> department) {
        this.departments = department;
    }

    //equals and hashcode methods overriden



}


import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQuery;
import javax.persistence.SequenceGenerator;
import javax.persistence.Table;

@Entity
@Table(name="DEPARTMENT")
public class Department {

    @Id
    @Column(name="ID")
    @SequenceGenerator(name="seq",sequenceName="dept_seq", allocationSize=1)
    @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="seq")
    private Long deptId;

    @Column(name="DEPT_NAME")
    private String deptName;

    @Column(name="DEPT_BOSS")
    private String deptBoss;

    @ManyToOne
    @JoinColumn(name = "NAME", nullable = false)
    private Employee employee;


    public Department(Long deptId, String deptName, String deptBoss, Employee employee) {
        super();
        this.deptName = deptName;
        this.deptBoss = deptBoss;
        this.employee = employee;
    }

    public Long getDeptId() {
        return deptId;
    }

    public void setDeptId(Long deptId) {
        this.deptId = deptId;
    }

    public String getDeptName() {
        return deptName;
    }

    public void setDeptName(String deptName) {
        this.deptName = deptName;
    }

    public String getDeptBoss() {
        return deptBoss;
    }

    public void setDeptBoss(String deptBoss) {
        this.deptBoss = deptBoss;
    }

    public Employee getEmployee() {
        return employee;
    }

    public void setEmployee(Employee employee) {
        this.employee = employee;
    }


    //OVERRIDE EQUALS AND HASHCODE

}

我无法弄清楚代码中的问题。

Answer 1

AFAIK Hibernate需要每个实体的无参数构造函数。由于employee和department都定义了显式构造函数，因此也必须定义no-arg构造函数