如何摆脱;org.hibernate.transientObject异常“;?
我在执行以下场景时遇到了上述异常如何摆脱;org.hibernate.transientObject异常“;?,hibernate,jakarta-ee,jpa,Hibernate,Jakarta Ee,Jpa,我在执行以下场景时遇到了上述异常 学生和地址具有多对一关系,其中as学生和电话号码具有一对多关系。在EntityManager对象上调用persist方法以保存“Students”对象时,我遇到如下异常: org.hibernate.transientObject异常:对象引用未保存的 瞬态实例-刷新前保存瞬态实例: model.Students1.addressId->model.Address 可以采取哪些步骤来解决这个问题 详情如下: DAO类: 您应该定义级联。 级联意味着,如果对象“A
学生
和地址
具有多对一
关系,其中as学生
和电话号码
具有一对多
关系。在EntityManager对象上调用persist方法以保存“Students”对象时,我遇到如下异常:
org.hibernate.transientObject异常:对象引用未保存的
瞬态实例-刷新前保存瞬态实例:
model.Students1.addressId->model.Address
可以采取哪些步骤来解决这个问题
详情如下:
DAO类:
您应该定义级联。 级联意味着,如果对象“A”具有对象“B”(或这些对象的集合),则引用的“B”对象将按照级联定义的指示进行保存/更新
public class DAO {
public static void main(String[] arr){
EntityManagerFactory emf = Persistence.createEntityManagerFactory("OneToManyPU");
EntityManager em = emf.createEntityManager();
EntityTransaction tr= em.getTransaction();
try{
tr.begin();
PhoneNumbers p1 = new PhoneNumbers();
PhoneNumbers p2 = new PhoneNumbers();
p1.setPhoneType("mobile");
p1.setPhoneNo("9881592106");
p2.setPhoneType("landline");
p2.setPhoneNo("24214988");
Set<PhoneNumbers> phones = new HashSet<PhoneNumbers>();
phones.add(p1);
phones.add(p2);
em.persist(p1);
em.persist(p2);
Address a1 = new Address();
a1.setCity("Pune");
a1.setZip("400987");
Students1 s1 = new Students1();
s1.setName("Alka");
s1.setAddressId(a1);
s1.setPhoneNo(phones);
em.persist(s1);
tr.commit();
}
catch(Exception e){
e.printStackTrace();
}
finally{
emf.close();
}
}
}
@Entity
@Table(name = "STUDENTS")
public class Students1 implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "ID")
private Long id;
@Column(name = "NAME")
private String name;
@JoinColumn(name = "ADDRESS_ID", referencedColumnName = "ID")
@ManyToOne
private Address addressId;
@OneToMany(cascade ={CascadeType.MERGE,CascadeType.PERSIST})
@JoinTable(name="STUDENT_PHONE",joinColumns={@JoinColumn(name="STUDENTS.ID")},inverseJoinColumns={@JoinColumn(name="PHONENUMBERS.ID")})
private Set<PhoneNumbers> phoneNo = new HashSet<PhoneNumbers>();
public void setPhoneNo(Set<PhoneNumbers> phoneNo) {
this.phoneNo = phoneNo;
}
public Set<PhoneNumbers> getPhoneNo() {
return phoneNo;
}
public Students1() {
}
public Students1(Long id) {
this.id = id;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Address getAddressId() {
return addressId;
}
public void setAddressId(Address addressId) {
this.addressId = addressId;
}
@Entity
@Table(name = "ADDRESS")
public class Address implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "ID")
private Long id;
@Column(name = "CITY")
private String city;
@Column(name = "ZIP")
private String zip;
@OneToMany(mappedBy = "addressId")
private Collection<Students1> students1Collection;
public Address() {
}
public Address(Long id) {
this.id = id;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getZip() {
return zip;
}
public void setZip(String zip) {
this.zip = zip;
}
public Collection<Students1> getStudents1Collection() {
return students1Collection;
}
public void setStudents1Collection(Collection<Students1> students1Collection) {
this.students1Collection = students1Collection;
}
}
@Entity
public class PhoneNumbers implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
@Column(name="PhoneNo")
private String phoneNo;
@Column(name="PhoneType")
private String phoneType;
public String getPhoneNo() {
return phoneNo;
}
public void setPhoneNo(String phoneNo) {
this.phoneNo = phoneNo;
}
public String getPhoneType() {
return phoneType;
}
public void setPhoneType(String phoneType) {
this.phoneType = phoneType;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
}