JPA how to update existing object data without exception?

Question

I try to update existing data rows in database but i get that exception:

[EL Warning]: 2012-10-24 20:02:27.798--UnitOfWork(22664464)--Exception [EclipseLink-4002] (Eclipse Persistence Services -
2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.DatabaseException Internal Exception: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '20-http://www.vilpra.lt/products/Foto/Aremikas/Katilas_zvake_big' for key 'PRIMARY' Error Code: 1062 Call: INSERT INTO x_links_media (image, link_id) VALUES (?, ?)  bind => [2 parameters bound] Query: InsertObjectQuery(database.entity.XLinksMedia[ xLinksMediaPK=database.entity.XLinksMediaPK[ linkId=20, image=http://www.link.lt/products.jpg ] ])

The main object class is look like code below. There is some variables with relation OneToMany.

package database.entity;

import java.io.Serializable;
import java.util.Date;
import java.util.List;
import javax.persistence.Basic;
import javax.persistence.CascadeType;
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.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.persistence.OneToOne;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.xml.bind.annotation.XmlRootElement;

@Entity
@Table(name = "x_parser_links")
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "XParserLinks.findAll", query = "SELECT x FROM XParserLinks x"),
    @NamedQuery(name = "XParserLinks.findByLinkId", query = "SELECT x FROM XParserLinks x WHERE x.linkId = :linkId"),
    @NamedQuery(name = "XParserLinks.findByPageId", query = "SELECT x FROM XParserLinks x WHERE x.pageId = :pageId"),
    @NamedQuery(name = "XParserLinks.findByLink", query = "SELECT x FROM XParserLinks x WHERE x.link = :link"),
    @NamedQuery(name = "XParserLinks.findByLevel", query = "SELECT x FROM XParserLinks x WHERE x.level = :level"),
    @NamedQuery(name = "XParserLinks.findByLinkType", query = "SELECT x FROM XParserLinks x WHERE x.linkType = :linkType"),
    @NamedQuery(name = "XParserLinks.findByCreateDate", query = "SELECT x FROM XParserLinks x WHERE x.createDate = :createDate"),
    @NamedQuery(name = "XParserLinks.findByDelDate", query = "SELECT x FROM XParserLinks x WHERE x.delDate = :delDate")})
public class XParserLinks implements Serializable {

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "link_id")
    private Integer linkId;
    @Column(name = "page_id")
    private Integer pageId;
    @Column(name = "link")
    private String link;
    @Column(name = "level")
    private Integer level;
    @Column(name = "link_type")
    private Short linkType;
    @Column(name = "create_date")
    @Temporal(TemporalType.TIMESTAMP)
    private Date createDate;
    @Column(name = "del_date")
    @Temporal(TemporalType.TIMESTAMP)
    private Date delDate;
    @JoinColumn(name = "tev_link_id")
    @OneToOne(cascade = CascadeType.ALL)
    private XParserLinks tevas;
    @OneToMany(mappedBy = "xParserLink", targetEntity = XLinksMedia.class, cascade = CascadeType.ALL)
    private List<XLinksMedia> fotos;
    @OneToMany(mappedBy = "xParserLink", targetEntity = XLinksVarchar.class, cascade = CascadeType.ALL)
    private List<XLinksVarchar> atributes;    

    public XParserLinks() {
    }

    public XParserLinks(Integer linkId) {
        this.linkId = linkId;
    }

    public Integer getLinkId() {
        return linkId;
    }

    public void setLinkId(Integer linkId) {
        this.linkId = linkId;
    }

    public Integer getPageId() {
        return pageId;
    }

    public void setPageId(Integer pageId) {
        this.pageId = pageId;
    }

    public String getLink() {
        return link;
    }

    public void setLink(String link) {
        this.link = link;
    }

    public Integer getLevel() {
        return level;
    }

    public void setLevel(Integer level) {
        this.level = level;
    }

    public Short getLinkType() {
        return linkType;
    }

    public void setLinkType(Short linkType) {
        this.linkType = linkType;
    }

    public Date getCreateDate() {
        return createDate;
    }

    public void setCreateDate(Date createDate) {
        this.createDate = createDate;
    }

    public Date getDelDate() {
        return delDate;
    }

    public void setDelDate(Date delDate) {
        this.delDate = delDate;
    }

    public XParserLinks getTevas() {
        return tevas;
    }

    public void setTevas(XParserLinks tevas) {
        this.tevas = tevas;
    }

    public List<XLinksMedia> getFotos() {
        return fotos;
    }

    public void setFotos(List<XLinksMedia> fotos) {
        this.fotos = fotos;
    }

    public List<XLinksVarchar> getAtributes() {
        return atributes;
    }

    public void setAtributes(List<XLinksVarchar> atributes) {
        this.atributes = atributes;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (linkId != null ? linkId.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 XParserLinks)) {
            return false;
        }
        XParserLinks other = (XParserLinks) object;
        if ((this.linkId == null && other.linkId != null) || (this.linkId != null && !this.linkId.equals(other.linkId))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "database.entity.XParserLinks[ linkId=" + linkId + " ]";
    }
}

And here is code where I want to proceed data. XParserLinks object is the man object like code above. In this example I check if object do not have his primary key LinkId then create new object with persist, but else just update object and his values, but I get exception like I mean before when I want to update existing object.

        XParserLinks e = entry.getValue();

        if (e.getLinkId() == null) {
            try {
                TarpineManager.startTransaction();

                TarpineManager.persist(e);

                TarpineManager.commitTransaction();

            } catch (Exception ex) {
                ex.printStackTrace();
                if (TarpineManager.getInstance().getTransaction().isActive()) {
                    TarpineManager.rollbackTransaction();
                }
            }
        } else {

            try {

                TarpineManager.startTransaction();

                TarpineManager.commitTransaction();

            } catch (Exception ex) {
                ex.printStackTrace();
                if (TarpineManager.getInstance().getTransaction().isActive()) {
                    TarpineManager.rollbackTransaction();
                }
            }

        }

Answer 1

Are you, by any chance, creating your entity and setting its Id by force? I see your class has a setLinkId(Integer linkId) method on it.

First of all, you should be using merge instead of persist. Now, whit this in mind, the exception is also being thrown by the merge method because JPA can't define if the entity you want to persist is a new one or it's a previosuly fetched one, because the states in the lifecycle aren't the same.

If you create an object and set its id, that entity has the state new, but if you fetched the entity before it should have a detached state. When merged, a detached entity will be correctly updated but a new entity will be persisted and, since the id is taken, the exception is thrown.

You have the entity's ID, so you better fetch them before, update the object and then merge them.