@Entity
@Table (name="TableA")
@SecondaryTable(name = "join_table_name", pkJoinColumns = {
        @PrimaryKeyJoinColumn(name = "ref_id1", referencedColumnName = "id1"),
        @PrimaryKeyJoinColumn(name = "ref_id2", referencedColumnName = "id2") })
public class ClassA {
   
    @EmbeddedId
    private CompositeId id;
   
    @OneToMany
    @JoinTable(name="join_table_name",joinColumns = @JoinColumn(name="refer_b_id"),
            inverseJoinColumns = {@JoinColumn(name="ref_id1"),@JoinColumn(name="ref_id2")})
    private ClassB b;
   
   
}

@Embeddable
class CompositeId implements Serializable{
   
   
    private static final long serialVersionUID = -2655072024737775697L;

    @Column(name="id1")
    private int id1;
   
    @Column(name="id2")
    private int id2;
   
    //Need to define default constructor
    public CompositeId(){}

    //MOST IMPORTANT :Implement this method properly
    public boolean equals(Object obj) {

        return super.equals(obj);
    }

    //MOST IMPORTANT :Implement this method properly
    public int hashCode() {

        return super.hashCode();
    }
   
}

@Entity
@Table(name="TableB")
class ClassB{
   //
   
}