Many to One Relationship with #IdClass - spring-boot

Question

Using Spring Data JPA & Hibernate, I am saving an object Company, that has 0 to Many AccountMapping. The AccountMappings Primary Key is a composite of a String accountNumber and the Company Primary Key. When I save a new company the COMP_NUM from the Company Object is not set into the AccountMapping object. When I use long companyNumber it is zero, and Long it is NUM. Hibernate is executing the insert statement first, but how to get it to set the primary key from company into child object ?
#Entity
#Table(name = "COMPANY")
public class Company implements Serializable {
#Id
#Column(name = "COMP_NUM")
#SequenceGenerator(name = "comp_num_seq", sequenceName = "comp_num_seq", allocationSize = 1)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "comp_num_seq")
private long number;
#OneToMany(mappedBy = "companyNumber", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
private List<AccountMapping> accountMappings;
public Company() {
super();
}
public long getNumber() {
return this.number;
}
public void setNumber(long id) {
this.number = id;
}
public List<AccountMapping> getAccountMappings() {
return accountMappings;
}
public void setAccountMappings(List<AccountMapping> accountMappings) {
this.accountMappings = accountMappings;
}
}
#Entity
#IdClass(value = AccountMappingPK.class)
#Table(name = "ACCOUNT_MAPPING")
public class AccountMapping implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#Column(name = "ACCNT_NUM")
private String accountNumber;
#Id
#Column(name = "COMP_NUM")
private Long companyNumber;
#Column(name = "IS_PRIMARY")
private Boolean isPrimary;
public String getAccountNumber() {
return accountNumber;
}
public void setAccountNumber(String accountNumber) {
this.accountNumber = accountNumber;
}
public Long getCompanyNumber() {
return companyNumber;
}
public void setCompanyNumber(Long companyNumber) {
this.companyNumber = companyNumber;
}
public Boolean getIsPrimary() {
return isPrimary;
}
public void setIsPrimary(Boolean isPrimary) {
this.isPrimary = isPrimary;
}
}
public class AccountMapping implements Serializable {
#Column(name = "EA_ACCNT_NUM", nullable = false)
private String accountNumber;
#Column(name = "COMP_NUM", nullable = false)
private Long companyNumber;
public AccountMapping() {
// default constructor
}
public String getAccountNumber() {
return accountNumber;
}
public void setAccountNum(String accountNumber) {
this.accountNumber = accountNumber;
}
public Long getCompanyNumber() {
return companyNumber;
}
public void setCompanyNumber(Long companyNumber) {
this.companyNumber = companyNumber;
}
#Override
public boolean equals(Object obj) {
if (obj instanceof AccountMappingPK) {
AccountMappingPK accntPk = (AccountMappingPK) obj;
if (!(accountNumber.equals(accntPk.getAccountNumber()))) {
return false;
}
if (!(accntPk.getCompanyNumber() == (companyNumber))) {
return false;
}
return true;
}
return false;
}
#Override
public int hashCode() {
int hash = (accountNumber == null ? 1 : accountNumber.hashCode());
return (int) (hash * companyNumber);
}
}

Answer 1

#Entity
#IdClass(value = AccountMappingPK.class)
#Table(name = "ACCOUNT_MAPPING")
public class AccountMapping implements Serializable {
#Id
#Column(name = "ACCNT_NUM")
private String accountNumber;
#Id
#ManyToOne
#JoinColumn(name = "COMP_NUM")
private Company company;
...
}
// No annotations in this class
public class AccountMappingPK implements Serializable {
private String accountNumber;
private Company company;
...
// All the getter/setter, constructors, and so on ...
}
The Hibernate ORM documentation has more details about mapping with #IdClass: See Example 134. IdClass with #ManyToOne