[java] Hibernate: ids for this class must be manually assigned before calling save()

I am having some problems with Hibernate and the oneToMany mapping.

Here is my function:

        Location location = new Location();
        location.setDateTime(new Date());
        location.setLatitude(lat);
        location.setLongitude(lon);

        location = this.locationDao.save(location);

        merchant = new Merchant();
        merchant.setAddress(address);
        merchant.setCity(city);
        merchant.setCountry(country);
        merchant.setLocation(location);
        merchant.setName(name);
        merchant.setOrganization(organization);
        merchant.setPublicId(publicId);
        merchant.setZipCode(zipCode);
        merchant.setApplication(this.applicationDAO.findByPublicId(applicationPublicId));

        merchant = this.merchantDao.save(merchant);

        return merchant;

Here are my two entities:

Location

import java.io.Serializable;
import java.util.Date;
import java.util.List;
import javax.persistence.*;
import javax.validation.constraints.NotNull;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlTransient;


@Entity
@Table(name = "location")
@XmlRootElement
public class Location implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "id", nullable = false)
    private Long id;

    @Basic(optional = false)
    @NotNull
    @Column(name = "latitude", nullable = false)
    private double latitude;

    @Basic(optional = false)
    @NotNull
    @Column(name = "longitude", nullable = false)
    private double longitude;

    @Basic(optional = false)
    @NotNull
    @Column(name = "date_time", nullable = false)
    @Temporal(TemporalType.TIMESTAMP)
    private Date dateTime;

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "location")
    private List<Merchant> retailerList;

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "location")
    private List<MobileUser> userList;

    public Location() {
    }

    public Location(Long id) {
        this.id = id;
    }

    public Location(Long id, double latitude, double longitude, Date dateTime) {
        this.id = id;
        this.latitude = latitude;
        this.longitude = longitude;
        this.dateTime = dateTime;
    }

    public Long getId() {
        return id;
    }
    //getters and setters


    @XmlTransient
    public List<Merchant> getRetailerList() {
        return retailerList;
    }

    public void setRetailerList(List<Merchant> retailerList) {
        this.retailerList = retailerList;
    }

    @XmlTransient
    public List<MobileUser> getUserList() {
        return userList;
    }

    public void setUserList(List<MobileUser> userList) {
        this.userList = userList;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (id != null ? id.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof Location)) {
            return false;
        }
        Location other = (Location) object;
        if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "com.fgsecure.geoloc.entities.Location[ id=" + id + " ]";
    }

Merchant

import java.io.Serializable;
import javax.persistence.*;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import javax.xml.bind.annotation.XmlRootElement;
import org.codehaus.jackson.annotate.JsonAutoDetect;
import org.codehaus.jackson.annotate.JsonIgnore;


@JsonAutoDetect
@Entity
@Table(name = "retailer")
@XmlRootElement

public class Merchant implements Serializable {

    private static final long serialVersionUID = 1L;
    @JsonIgnore
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "id", nullable = false)
    private Long id;
    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 50)
    @Column(name = "public_id", nullable = false, length = 50)
    private String publicId;
    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 50)
    @Column(name = "name", nullable = false, length = 50)
    private String name;
    @Size(max = 50)
    @Column(name = "organization", length = 50)
    private String organization;
    @Size(max = 128)
    @Column(name = "address", length = 128)
    private String address;
    @Size(max = 10)
    @Column(name = "zip_code", length = 10)
    private String zipCode;
    @Size(max = 50)
    @Column(name = "city", length = 50)
    private String city;
    @Size(max = 50)
    @Column(name = "country", length = 50)
    private String country;
    @JoinColumn(name = "location_id", referencedColumnName = "id", nullable = false)
    @ManyToOne(optional = false)
    private Location location;
    @JoinColumn(name = "application_id", referencedColumnName = "id", nullable = false)
    @ManyToOne(optional = false)
    private Application application;


    public Merchant() {
    }

    public Merchant(Long id) {
        this.id = id;
    }

    public Merchant(Long id, String publicId, String name) {
        this.id = id;
        this.publicId = publicId;
        this.name = name;
    }

   //getters and setters


    @Override
    public int hashCode() {
        int hash = 0;
        hash += (id != null ? id.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof Merchant)) {
            return false;
        }
        Merchant other = (Merchant) object;
        if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "com.fgsecure.geoloc.entities.Retailer[ id=" + id + " ]";
    }
}

And each time I am calling my function I get:

org.hibernate.id.IdentifierGenerationException: ids for this class must be manually assigned before calling save():

for this line:

location = this.locationDao.save(location);

I don't understand why. Because in that case there is no need to manually assigne the id of location as it is auto generated. I must have done something wrong but after 3 days looking I don't find.

I am using PostGreSQL and the id is an autogenerated ID with this sequence:

nextval('location_id_seq'::regclass)`

EDIT SOLVE:

Ok Thanks for your answers.

If it can help other person in the future, just need to modify the param of the id by:

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "id",unique=true, nullable = false)

Assign primary key in hibernate

Make sure that the attribute is primary key and Auto Incrementable in the database. Then map it into the data class with the annotation with @GeneratedValue annotation using IDENTITY.

@Entity
@Table(name = "client")
data class Client(
        @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "id") private val id: Int? = null
)

GL

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