Develop Reference

PostgreSQL not doing autoincrement

I am using postgresql with springboot. So whenever I am using post method to add a new detail in my table instead of autoincrementing id it's going from 1 to 3. It's taking alternate values rather than consecutive values. I have given following properties and then created table:
spring.jpa.hibernate.ddl-auto=create
Didn't create the table manually. What is the reason for this error? This is my entity class.
#Entity
#Table(name = "NORTHBOUND_SUBSCRIPTION")
public class NBSubscription {
#Id
#GeneratedValue
#Column(name = "nb_id")
private Long nbId;
#Column(name = "DEVICE_FILTER")
private String deviceFilter;
#Column(name = "INTERFACE_FILTER")
private String interfaceFilter;
#ManyToOne
#JoinColumn(name="subscriber_id", referencedColumnName="SUBSCRIBER_ID")
private Subscriber subscriber;
#OneToOne
#JoinColumn(name="sensor_group_id", referencedColumnName="ID")
private SensorGroup sensorGroup;
#Column(name = "EVENT_TYPE")
private String eventType;
#Column(name = "SAMPLING_INTERVAL")
private Integer samplingInterval;
#Column(name = "CREATEAT")
#DateTimeFormat(pattern = "dd-MM-yyyy HH:mm")
private Timestamp createAt;
#Column(name = "MODIFIEDAT")
#DateTimeFormat(pattern = "dd-MM-yyyy HH:mm")
private Timestamp modifiedAt;
#Column(name = "CREATEDBY")
private String createdBy;
#Column(name = "MODIFIEDBY")
private String modifiedBy;
#Column(name = "mark_deletion")
private String markDeletion;
public NBSubscription() {
super();
}
public NBSubscription(Subscriber subscriber, SensorGroup sensorGroup) {
super();
this.subscriber = subscriber;
this.sensorGroup = sensorGroup;
}
public Long getNbId() {
return nbId;
}
public void setNbId(Long nbId) {
this.nbId = nbId;
}
public String getDeviceFilter() {
return deviceFilter;
}
public void setDeviceFilter(String deviceFilter) {
this.deviceFilter = deviceFilter;
}
public String getInterfaceFilter() {
return interfaceFilter;
}
public void setInterfaceFilter(String interfaceFilter) {
this.interfaceFilter = interfaceFilter;
}
#JsonIgnore
public Subscriber getSubscriber() {
return subscriber;
}
public void setSubscriber(Subscriber subscriber) {
this.subscriber = subscriber;
}
public SensorGroup getSensorGroup() {
return sensorGroup;
}
public void setSensorGroup(SensorGroup sensorGroup) {
this.sensorGroup = sensorGroup;
}
public Integer getSamplingInterval() {
return samplingInterval;
}
public void setSamplingInterval(Integer samplingInterval) {
this.samplingInterval = samplingInterval;
}
public String getEventType() {
return eventType;
}
public void setEventType(String eventType) {
this.eventType = eventType;
}
public Timestamp getCreateAt() {
return createAt;
}
public void setCreateAt(Timestamp createAt) {
this.createAt = createAt;
}
public Timestamp getModifiedAt() {
return modifiedAt;
}
public void setModifiedAt(Timestamp modifiedAt) {
this.modifiedAt = modifiedAt;
}
public String getMarkDeletion() {
return markDeletion;
}
public void setMarkDeletion(String markDeletion) {
this.markDeletion = markDeletion;
}
public String getCreatedBy() {
return createdBy;
}
public void setCreatedBy(String createdBy) {
this.createdBy = createdBy;
}
public String getModifiedBy() {
return modifiedBy;
}
public void setModifiedBy(String modifiedBy) {
this.modifiedBy = modifiedBy;
}

Try this
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
if it doesn't work, try using the table sequence
#Id
#GeneratedValue(strategy=SEQUENCE, generator="CUST_SEQ")

Your autoincrement is implemented with a sequence, and by default entities share the same sequence, so the autoincrement values get spread across the entities.
You could assign each entity its own sequence. But be aware sequences don't participate in transactions. That means if you have a rollback there will be a break in the numbering. Occasional gaps are not avoidable.
If you are making this sequence visible to users and they expect the numbering to be contiguous, my advice is to not use a sequence for that, and keep the user-visible counter in a field separate from the id. If it is visible to users, then at some point it will need to change, and you can't change ids.

Find By category_id Hibernate, Spring

I'm a student, new to Stack Overflow, spring-boot and hibernate stack.
The problem: return a list of questions based on their category id.
As the in my model entity classes below I have no attributes for categoryId(foreign key) as this is being generated automatically through the relationship annotations.
I seem to be able to return a list of all questions with no level of filtering, but would also like a method that returns the questions based on their category id(foreign key).
Any help would be greatly appreciated, Thanks!
Using hibernate 5.2
categoryModel
#Entity
public class Category {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#NotNull
#Size(min = 3, max = 20)
private String name;
#NotNull
#Pattern(regexp = "#[0-9a-fA-F]{6}")
private String colorCode;
#OneToMany(mappedBy = "category")
private List<Question> questions = new ArrayList<>();
public Category(){}
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 List<Question> getQuestions() {
return questions;
}
public String getColorCode() {
return colorCode;
}
public void setColorCode(String colorCode) {
this.colorCode = colorCode;
}
questionModel
#Entity
public class Question {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
#ManyToOne
private Category category;
private LocalDateTime dateCreated = LocalDateTime.now();
public Question(){}
public String getTimeSinceUploaded() {
String unit = "";
LocalDateTime now = LocalDateTime.now();
long diff;
if((diff = ChronoUnit.SECONDS.between(dateCreated,now)) < 60){
unit = "secs";
} else if ((diff = ChronoUnit.MINUTES.between(dateCreated,now)) < 60) {
unit = "mins";
} else if ((diff = ChronoUnit.HOURS.between(dateCreated,now)) < 24) {
unit = "hours";
} else if ((diff = ChronoUnit.DAYS.between(dateCreated,now)) < 30) {
unit = "days";
} else if ((diff = ChronoUnit.MONTHS.between(dateCreated,now)) < 12) {
unit = "months";
} else{
diff = ChronoUnit.YEARS.between(dateCreated,now);
}
return String.format("%d %s",diff,unit);
}
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 Category getCategory() {
return category;
}
public void setCategory(Category category) {
this.category = category;
}
public LocalDateTime getDateCreated() {
return dateCreated;
}
public void setDateCreated(LocalDateTime dateCreated) {
this.dateCreated = dateCreated;
}
}
question DAO
#Repository
public class QuestionDaoImpl implements IQuestionDao {
#Autowired
private SessionFactory sessionFactory;
/**
* Returns a list of all the questions - michael
*/
#Override
public List<Question> findAll() {
Session session = sessionFactory.openSession();
// Create CriteriaBuilder
CriteriaBuilder builder = session.getCriteriaBuilder();
// Create CriteriaQuery
CriteriaQuery<Question> criteria = builder.createQuery(Question.class);
// Specify criteria root
criteria.from(Question.class);
// Execute query
List<Question> questions = session.createQuery(criteria).getResultList();
session.close();
return questions;
}
/**
* Returns A question by using the id - michael
*/
#Override
public Question findById(Long id) {
Session session = sessionFactory.openSession();
Question question = session.get(Question.class, id);
session.close();
return question;
}
/**
* TODO: ml- Finds a list of questions according to the category_id
*/
#Override
public List<Question> findByCategoryId(Long categoryId){
// This is a issue i a have here
return null;
}

try this, you have to pass category object bcz you created object in question entity,
#Override
public List<Question> findByCategoryId(Long categoryId){
Session session = sessionFactory.openSession();
final Criteria cr = session.createCriteria(Question.class);
cr.add(Restrictions.eq("category", category));
return cr.list();
}
Let me know if any quires.

Is your Dao extends crudrepository or JpaRepository?

Persisting a table with foreign keys using EJB and JPA

I am new to JavaEE and I am having a problem with persisting a table that has foreign keys pointing to the primary key of another table using entity classes and ejb's entity manager. I am using Netbeans.
I have an entity called 'property' and have another entity called 'offer' which holds the foreign key pointing to the primary key of the property. So basically, the logic is that one property can have many offers. Therefore, I am trying to add new offers in the 'offer' table using the entity manager but I am not being able to do it. You can look at the code and see what I maybe missing.
Property entity:
#Entity
#Table(name = "PROPERTY")
#XmlRootElement
#NamedQueries({
#NamedQuery(name = "Property.findAll", query = "SELECT p FROM Property p")})
public class Property implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#Column(name = "PROPERTYID")
private Integer propertyid;
#Basic(optional = false)
#NotNull
#Size(min = 1, max = 500)
#Column(name = "DESCRIPTION")
private String description;
#Size(max = 50)
#Column(name = "TYPE")
private String type;
#Column(name = "NUMBEROFBEDROOM")
private Integer numberofbedroom;
#Column(name = "NUMBEROFBATHROOM")
private Integer numberofbathroom;
#Basic(optional = false)
#NotNull
#Size(min = 1, max = 10)
#Column(name = "ISFURNISHED")
private String isfurnished;
#Basic(optional = false)
#NotNull
#Size(min = 1, max = 10)
#Column(name = "HASGARDEN")
private String hasgarden;
#Basic(optional = false)
#NotNull
#Size(min = 1, max = 20)
#Column(name = "SIZE")
private String size;
#Basic(optional = false)
#NotNull
#Size(min = 1, max = 100)
#Column(name = "PRICE")
private String price;
#Basic(optional = false)
#NotNull
#Column(name = "ENTEREDDATE")
#Temporal(TemporalType.DATE)
private Date entereddate;
#Basic(optional = false)
#NotNull
#Column(name = "ENTEREDTIME")
#Temporal(TemporalType.TIME)
private Date enteredtime;
#OneToOne(cascade = CascadeType.ALL, mappedBy = "property")
private Paddress paddress;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "propertyid")
private Collection<Offer> offerCollection;
#JoinColumn(name = "PROPERTYOWNERID", referencedColumnName = "PROPERTYOWNERID")
#ManyToOne(optional = false)
private Propertyowner propertyownerid;
#JoinColumn(name = "REALESTATEAGENTID", referencedColumnName = "REALESTATEAGENTID")
#ManyToOne(optional = false)
private Realestateagent realestateagentid;
public Property() {
}
public Property(Integer propertyid) {
this.propertyid = propertyid;
}
public Property(Integer propertyid, String description, String isfurnished, String hasgarden, String size, String price, Date entereddate, Date enteredtime) {
this.propertyid = propertyid;
this.description = description;
this.isfurnished = isfurnished;
this.hasgarden = hasgarden;
this.size = size;
this.price = price;
this.entereddate = entereddate;
this.enteredtime = enteredtime;
}
public Integer getPropertyid() {
return propertyid;
}
public void setPropertyid(Integer propertyid) {
this.propertyid = propertyid;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public Integer getNumberofbedroom() {
return numberofbedroom;
}
public void setNumberofbedroom(Integer numberofbedroom) {
this.numberofbedroom = numberofbedroom;
}
public Integer getNumberofbathroom() {
return numberofbathroom;
}
public void setNumberofbathroom(Integer numberofbathroom) {
this.numberofbathroom = numberofbathroom;
}
public String getIsfurnished() {
return isfurnished;
}
public void setIsfurnished(String isfurnished) {
this.isfurnished = isfurnished;
}
public String getHasgarden() {
return hasgarden;
}
public void setHasgarden(String hasgarden) {
this.hasgarden = hasgarden;
}
public String getSize() {
return size;
}
public void setSize(String size) {
this.size = size;
}
public String getPrice() {
return price;
}
public void setPrice(String price) {
this.price = price;
}
public Date getEntereddate() {
return entereddate;
}
public void setEntereddate(Date entereddate) {
this.entereddate = entereddate;
}
public Date getEnteredtime() {
return enteredtime;
}
public void setEnteredtime(Date enteredtime) {
this.enteredtime = enteredtime;
}
public Paddress getPaddress() {
return paddress;
}
public void setPaddress(Paddress paddress) {
this.paddress = paddress;
}
#XmlTransient
public Collection<Offer> getOfferCollection() {
return offerCollection;
}
public void setOfferCollection(Collection<Offer> offerCollection) {
this.offerCollection = offerCollection;
}
public Propertyowner getPropertyownerid() {
return propertyownerid;
}
public void setPropertyownerid(Propertyowner propertyownerid) {
this.propertyownerid = propertyownerid;
}
public Realestateagent getRealestateagentid() {
return realestateagentid;
}
public void setRealestateagentid(Realestateagent realestateagentid) {
this.realestateagentid = realestateagentid;
}
public String dateToString()
{
DateFormat df = new SimpleDateFormat("dd/MM/yy");
return df.format(entereddate);
}
public String timeToString()
{
DateFormat df = new SimpleDateFormat("HH:mm:ss");
return df.format(enteredtime);
}
#Override
public int hashCode() {
int hash = 0;
hash += (propertyid != null ? propertyid.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 Property)) {
return false;
}
Property other = (Property) object;
if ((this.propertyid == null && other.propertyid != null) || (this.propertyid != null && !this.propertyid.equals(other.propertyid))) {
return false;
}
return true;
}
#Override
public String toString() {
return "com.sushan.model.Property[ propertyid=" + propertyid + " ]";
}
}
EJB PropertyDAO:
#Stateless
public class PropertyDAO implements PropertyDAOLocal {
#PersistenceContext(unitName="RealEstateWebsite-ejbPU")
private EntityManager em;
#Override
public void AddProperty(Property property) {
em.persist(property);
}
#Override
public void EditProperty(Property property) {
em.merge(property);
}
#Override
public void DeleteProperty(int propertyId) {
em.remove(GetProperty(propertyId));
}
#Override
public List<Property> GetAllProperty() {
return em.createNamedQuery("Property.findAll").getResultList();
}
#Override
public Property GetProperty(int propertyId) {
return em.find(Property.class, propertyId);
}
#Override
public void EditPropertyAddress(Paddress propertyAddress) {
em.merge(propertyAddress);
}
}
Offer entity:
#Entity
#Table(name = "OFFER")
#XmlRootElement
#NamedQueries({
#NamedQuery(name = "Offer.findAll", query = "SELECT o FROM Offer o")})
public class Offer implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#Column(name = "OFFERID")
private Integer offerid;
#Basic(optional = false)
#NotNull
#Size(min = 1, max = 100)
#Column(name = "OFFERSTATUS")
private String offerstatus;
#Basic(optional = false)
#NotNull
#Size(min = 1, max = 100)
#Column(name = "ORIGINALOFFER")
private String originaloffer;
#Basic(optional = false)
#NotNull
#Size(min = 1, max = 100)
#Column(name = "OFFERINGBP")
private String offeringbp;
#Basic(optional = false)
#NotNull
#Column(name = "OFFEREDDATE")
#Temporal(TemporalType.DATE)
private Date offereddate;
#Basic(optional = false)
#NotNull
#Column(name = "OFFEREDTIME")
#Temporal(TemporalType.TIME)
private Date offeredtime;
#JoinColumn(name = "BUYERID", referencedColumnName = "BUYERID")
#ManyToOne(optional = false)
private Buyer buyerid;
#JoinColumn(name = "PROPERTYID", referencedColumnName = "PROPERTYID")
#ManyToOne(optional = false)
private Property propertyid;
public Offer() {
}
public Offer(Integer offerid) {
this.offerid = offerid;
}
public Offer(String offerstatus, String originaloffer, String offeringbp, Date offereddate, Date offeredtime, Buyer buyerid, Property propertyid) {
this.offerstatus = offerstatus;
this.originaloffer = originaloffer;
this.offeringbp = offeringbp;
this.offereddate = offereddate;
this.offeredtime = offeredtime;
this.buyerid = buyerid;
this.propertyid = propertyid;
}
public Integer getOfferid() {
return offerid;
}
public void setOfferid(Integer offerid) {
this.offerid = offerid;
}
public String getOfferstatus() {
return offerstatus;
}
public void setOfferstatus(String offerstatus) {
this.offerstatus = offerstatus;
}
public String getOriginaloffer() {
return originaloffer;
}
public void setOriginaloffer(String originaloffer) {
this.originaloffer = originaloffer;
}
public String getOfferingbp() {
return offeringbp;
}
public void setOfferingbp(String offeringbp) {
this.offeringbp = offeringbp;
}
public Date getOffereddate() {
return offereddate;
}
public void setOffereddate(Date offereddate) {
this.offereddate = offereddate;
}
public Date getOfferedtime() {
return offeredtime;
}
public void setOfferedtime(Date offeredtime) {
this.offeredtime = offeredtime;
}
public Buyer getBuyerid() {
return buyerid;
}
public void setBuyerid(Buyer buyerid) {
this.buyerid = buyerid;
}
public Property getPropertyid() {
return propertyid;
}
public void setPropertyid(Property propertyid) {
this.propertyid = propertyid;
}
#Override
public int hashCode() {
int hash = 0;
hash += (offerid != null ? offerid.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 Offer)) {
return false;
}
Offer other = (Offer) object;
if ((this.offerid == null && other.offerid != null) || (this.offerid != null && !this.offerid.equals(other.offerid))) {
return false;
}
return true;
}
#Override
public String toString() {
return "com.sushan.model.Offer[ offerid=" + offerid + " ]";
}
EJB OfferDAO:
#Stateless
public class OfferDAO implements OfferDAOLocal {
#PersistenceContext(unitName="RealEstateWebsite-ejbPU")
EntityManager em;
#Override
public void EditOffer(Offer offer) {
em.merge(offer);
}
#Override
public List<Offer> GetAllOffer(int propertyId) {
return em.createNamedQuery("Offer.findByPropertyID").setParameter("propertyID", propertyId).getResultList();
}
#Override
public List<Offer> GetAllOffer() {
return em.createNamedQuery("Offer.findAll").getResultList();
}
#Override
public void Add(Offer offer) {
em.persist(offer);
}
}
Servlet that connects the JSP with the EJB:
String action = request.getParameter("action");
String currencyType = request.getParameter("ddlCurrencyType");
String amount = request.getParameter("offerAmount");
String propertyIdStr = request.getParameter("hdnbt");
if ("Offer".equalsIgnoreCase(action))
{
if ("".equals(action) & !"".equals(currencyType) & !"".equals(amount) & !"".equals(propertyIdStr))
{
DateFormat df = new SimpleDateFormat("dd/MM/yy");
DateFormat df1 = new SimpleDateFormat("HH:mm:ss");
Date currentDate = new Date();
Date currentTime = new Date();
int propertyId = Integer.parseInt(propertyIdStr);
try {
currentDate = df.parse(df.format(currentDate));
currentTime = df1.parse(df1.format(currentTime));
} catch (ParseException e) {
}
Buyer buyer = buyerDAO.GetBuyer(1);
Property property = propertyDAO.GetProperty(propertyId);
Offer offer = new Offer("Pending", amount, amount, currentDate, currentTime, buyer, property);
offerDAO.Add(offer);
}
else
{
}
}
request.setAttribute("allProperty", propertyDAO.GetAllProperty());
request.getRequestDispatcher("AdministerProperty.jsp").forward(request, response);
Am I missing something here? I have followed a tutorial which didn't have a foreign key guidance but tried to use my own logic to go around it but it didn't work. I cannot find a reliable source that uses the method similar to me. Most of the resources I find are for Hibernate but I am using EJB.

It seems that the method which retrieves the Property and the method that persists the Offer are run in a separate transactions (DAOs being the Stateless session beans).
That would mean that the Offer is populated and persisted with a detached Property, so the persistence provider is not aware of it.
Not sure why an exception is not raised but you would have to merge the Property first or do the query in the same transaction as you persist the Offer:
#Override
public void Add(Offer offer, int peropertyId) {
Property property = em.find(Property.class, propertyId);
offer.setPeropertyId(property);
em.persist(offer);
}
or
#Override
public void Add(Offer offer, Property peroperty) {
Property managedProperty = em.merge(property);
offer.setPeropertyId(managedProperty);
em.persist(offer);
}

I fixed it. If you look at the code for servlet, it was the problem with my if condition that checks the action parameter. It was meant to be if action is not empty but it checks if action is empty. I found this issue by creating an integer that increments itself when it reaches certain stages within the code.
I think you were right on the fact that I had to do the getting property id and buyer id on the same transaction. Otherwise that would have been the next issue for me. Thank you.

How to prevent endless loop in hibernate

I have a rest server and client which uses this API. I have a list of hotels and it had passed well until I added bidirectional dependencies to other entities.After that I start receive an endless array of entities which just repeat the same row in database.
It is my first project with hibernate so may be I made trivial mistakes of novice.
Hotel:
#Entity
#Table(name = "hotels", schema = "", catalog = "mydb")
public class HotelsEntity implements HospitalityEntity{
private int idHotel;
private String name;
private String region;
private String description;
// private byte[] photo;
private HotelPropertyEntity property;
private List<RoomEntity> rooms;
#OneToOne(mappedBy = "hotel")
public HotelPropertyEntity getProperty() {
return property;
}
public void setProperty(HotelPropertyEntity property) {
this.property = property;
}
#OneToMany(mappedBy = "hotel")
public List<RoomEntity> getRooms() {
return rooms;
}
public void setRooms(List<RoomEntity> rooms) {
this.rooms = rooms;
}
#Id
#Column(name = "id_hotel", unique = true)
#GeneratedValue(strategy=GenerationType.AUTO)
public int getIdHotel() {
return idHotel;
}
public void setIdHotel(int idHotel) {
this.idHotel = idHotel;
}
#Basic
#Column(name = "name")
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
#Basic
#Column(name = "region")
public String getRegion() {
return region;
}
public void setRegion(String region) {
this.region = region;
}
#Basic
#Column(name = "description")
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
HotelProperty
#Entity
#Table(name = "hotel_property", schema = "", catalog = "mydb")
public class HotelPropertyEntity {
private int idHotelProperty;
private byte hasPool;
private byte hasTennisCourt;
private byte hasWaterslides;
private HotelsEntity hotel;
#Id
#Column(name = "id_hotel_property", unique = true)
#GeneratedValue(strategy=GenerationType.AUTO)
public int getIdHotelProperty() {
return idHotelProperty;
}
public void setIdHotelProperty(int idHotelProperty) {
this.idHotelProperty = idHotelProperty;
}
#Basic
#Column(name = "has_pool", columnDefinition = "BIT", length = 1)
public byte getHasPool() {
return hasPool;
}
public void setHasPool(byte hasPool) {
this.hasPool = hasPool;
}
#Basic
#Column(name = "has_tennis_court", columnDefinition = "BIT", length = 1)
public byte getHasTennisCourt() {
return hasTennisCourt;
}
public void setHasTennisCourt(byte hasTennisCourt) {
this.hasTennisCourt = hasTennisCourt;
}
#Basic
#Column(name = "has_waterslides", columnDefinition = "BIT", length = 1)
public byte getHasWaterslides() {
return hasWaterslides;
}
public void setHasWaterslides(byte hasWaterslides) {
this.hasWaterslides = hasWaterslides;
}
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "id_hotel_property")
public HotelsEntity getHotel() {
return hotel;
}
public void setHotel(HotelsEntity hotel) {
this.hotel = hotel;
}
Room:
#Entity
#Table(name = "room", schema = "", catalog = "mydb")
public class RoomEntity {
private int idRoom;
private String roomType;
private int peopleCapacity;
private Boolean booked;
private Boolean locked;
private HotelsEntity hotel;
private InventoriesEntity inventory;
private RoomPropertyEntity roomProperty;
#OneToOne(mappedBy = "room")
public RoomPropertyEntity getRoom() {
return roomProperty;
}
public void setRoom(RoomPropertyEntity roomProperty) {
this.roomProperty = roomProperty;
}
#OneToOne
#JoinColumn(name = "id_room")
public InventoriesEntity getInventory() {
return inventory;
}
public void setInventory(InventoriesEntity inventory) {
this.inventory = inventory;
}
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "id_hotel")
public HotelsEntity getHotel() {
return hotel;
}
public void setHotel(HotelsEntity hotel) {
this.hotel = hotel;
}
#Id
#Column(name = "id_room")
public int getIdRoom() {
return idRoom;
}
public void setIdRoom(int idRoom) {
this.idRoom = idRoom;
}
#Basic
#Column(name = "room_type")
public String getRoomType() {
return roomType;
}
public void setRoomType(String roomType) {
this.roomType = roomType;
}
#Basic
#Column(name = "people_capacity")
public int getPeopleCapacity() {
return peopleCapacity;
}
public void setPeopleCapacity(int peopleCapacity) {
this.peopleCapacity = peopleCapacity;
}
#Basic
#Column(name = "booked", columnDefinition = "BIT", length = 1)
public Boolean getBooked() {
return booked;
}
public void setBooked(Boolean booked) {
this.booked = booked;
}
#Basic
#Column(name = "locked", columnDefinition = "BIT", length = 1)
public Boolean getLocked() {
return locked;
}
public void setLocked(Boolean locked) {
this.locked = locked;
}
Could you please advise what is a way or ways to tell hibernate to stop this cycle?
p.s
This code contains another one issue. I f I remove one to one dependency and remain only one to many I receive failed to lazily initialize a collection of role: com.example.model.HotelsEntity.rooms, could not initialize proxy - no Session (through reference chain: java.util.ArrayList[0]->com.example.model.HotelsEntity["rooms"])

You need to mark entity as not serializable for JSON. Please use #JsonIgnore or #JsonIgnoreProperties("field") on one of the sides of the relations (the annotation is class-level).

how to compare avoid insertion of duplicate data into arraylist

i have a class where i am inserting data into a array-list based on the id provided.
I am passing a bookId into my class and by comparing bookid i am get a book object. And after getting that object(book) ,am inserting into my arraylist.
Now I do't want to insert same data more then once. If a same bookid passes in the class then only it should store once.
i am storing my arraylist into session.
please check my code. And suggest me a solution for my problem.How to avoid duplicate insertion of data into my arraylist?
AddBookToSession.java
..................
...................
...................
private Integer bid; HttpServletRequest request = ServletActionContext.getRequest();
private Map<String, Object> session;
List<Bookdetails> books = new ArrayList<Bookdetails>();
private BookdetailsDAO dao = new BookdetailsDAO();
public String execute()
{
String bookid = request.getParameter("bid");
Bookdetails book = dao.listBookDetailsById(Integer.parseInt(bookid));
int checkduplicate=1;
//getting list from session to compare with the id
List list = (List) session.get( VisionBooksConstants.USER );
Iterator itr = list.iterator();
int bidd=0;
while(itr.hasNext())
{
Bookdetails bks=(Bookdetails) itr.next();
bidd=bks.getId(); //getting bookid from arraylist,which was stored in session
if (bidd==Integer.parseInt(bookid))
{
checkduplicate=0; //returns 0 ,so that i can compare it below to avoid duplicate data
}
}
//
if (book != null && checkduplicate==1 )
{
books = sessionBooks();
HttpServletRequest request = ServletActionContext.getRequest();
books.add(book);
System.out.println("books size"+books.size());
}
return SUCCESS;
}
........................
......................
Alternative solution
HashSet() update
public String execute()
{ HashSet<Bookdetails> books = new HashSet<Bookdetails>();
String bookid = request.getParameter("bid");
Bookdetails book = dao.listBookDetailsById(Integer.parseInt(bookid));
books = (HashSet<Bookdetails>) session.get(BillTransactionBooksConstants.BOK);
if ( books == null ) books = new HashSet<Bookdetails>();
boolean already_exists = false;
books.add(book);
System.out.println("books size"+books.size());
session.put(BillTransactionBooksConstants.BOK,books);
return SUCCESS;
}
Bookdetails.java(Pojo)
package v.esoft.pojos;
// Generated Nov 5, 2012 9:37:14 PM by Hibernate Tools 3.4.0.CR1
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import static javax.persistence.GenerationType.IDENTITY;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
/**
* Bookdetails generated by hbm2java
*/
#Entity
#Table(name = "bookdetails", catalog = "vbsoftware")
public class Bookdetails implements java.io.Serializable {
private Integer id;
private String isbn;
private String bookTitile;
private String authFirstname;
private String authLastname;
private String editionYear;
private Integer subjectId;
private Integer coverId;
private Integer languageId;
private String publisherName;
private Integer editionId;
private Float price;
private String quantity;
private String description;
private Integer locationId;
private String remarks;
private String img1;
private String img2;
private String videoUrl;
private Integer createrId;
private Date createdDate;
private Integer updateId;
private Date updatedDate;
public Bookdetails() {
}
public Bookdetails(String isbn, String bookTitile, String authFirstname,
String authLastname, String editionYear, Integer subjectId,
Integer coverId, Integer languageId, String publisherName,
Integer editionId, Float price, String quantity,
String description, Integer locationId, String remarks,
String img1, String img2, String videoUrl, Integer createrId,
Date createdDate, Integer updateId, Date updatedDate) {
this.isbn = isbn;
this.bookTitile = bookTitile;
this.authFirstname = authFirstname;
this.authLastname = authLastname;
this.editionYear = editionYear;
this.subjectId = subjectId;
this.coverId = coverId;
this.languageId = languageId;
this.publisherName = publisherName;
this.editionId = editionId;
this.price = price;
this.quantity = quantity;
this.description = description;
this.locationId = locationId;
this.remarks = remarks;
this.img1 = img1;
this.img2 = img2;
this.videoUrl = videoUrl;
this.createrId = createrId;
this.createdDate = createdDate;
this.updateId = updateId;
this.updatedDate = updatedDate;
}
#Id
#GeneratedValue(strategy = IDENTITY)
#Column(name = "id", unique = true, nullable = false)
public Integer getId() {
return this.id;
}
public void setId(Integer id) {
this.id = id;
}
//###########################################################################
// FOR HASHSETS EQUALS
//###########################################################################
public Bookdetails(int i){ id = i; }
public boolean equals(Object obj){
System.err.println("called"); // Never happens
return id == ((Bookdetails)obj).id;
}
#Column(name = "isbn", length = 90)
public String getIsbn() {
return this.isbn;
}
public void setIsbn(String isbn) {
this.isbn = isbn;
}
#Column(name = "book_titile")
public String getBookTitile() {
return this.bookTitile;
}
public void setBookTitile(String bookTitile) {
this.bookTitile = bookTitile;
}
#Column(name = "auth_firstname", length = 120)
public String getAuthFirstname() {
return this.authFirstname;
}
public void setAuthFirstname(String authFirstname) {
this.authFirstname = authFirstname;
}
#Column(name = "auth_lastname", length = 120)
public String getAuthLastname() {
return this.authLastname;
}
public void setAuthLastname(String authLastname) {
this.authLastname = authLastname;
}
#Column(name = "edition_year", length = 20)
public String getEditionYear() {
return this.editionYear;
}
public void setEditionYear(String editionYear) {
this.editionYear = editionYear;
}
#Column(name = "subject_id")
public Integer getSubjectId() {
return this.subjectId;
}
public void setSubjectId(Integer subjectId) {
this.subjectId = subjectId;
}
#Column(name = "cover_id")
public Integer getCoverId() {
return this.coverId;
}
public void setCoverId(Integer coverId) {
this.coverId = coverId;
}
#Column(name = "language_id")
public Integer getLanguageId() {
return this.languageId;
}
public void setLanguageId(Integer languageId) {
this.languageId = languageId;
}
#Column(name = "publisher_name", length = 70)
public String getPublisherName() {
return this.publisherName;
}
public void setPublisherName(String publisherName) {
this.publisherName = publisherName;
}
#Column(name = "edition_id")
public Integer getEditionId() {
return this.editionId;
}
public void setEditionId(Integer editionId) {
this.editionId = editionId;
}
#Column(name = "price", precision = 12, scale = 0)
public Float getPrice() {
return this.price;
}
public void setPrice(Float price) {
this.price = price;
}
#Column(name = "quantity", length = 40)
public String getQuantity() {
return this.quantity;
}
public void setQuantity(String quantity) {
this.quantity = quantity;
}
#Column(name = "description", length = 65535)
public String getDescription() {
return this.description;
}
public void setDescription(String description) {
this.description = description;
}
#Column(name = "location_id")
public Integer getLocationId() {
return this.locationId;
}
public void setLocationId(Integer locationId) {
this.locationId = locationId;
}
#Column(name = "remarks", length = 65535)
public String getRemarks() {
return this.remarks;
}
public void setRemarks(String remarks) {
this.remarks = remarks;
}
#Column(name = "img1")
public String getImg1() {
return this.img1;
}
public void setImg1(String img1) {
this.img1 = img1;
}
#Column(name = "img2")
public String getImg2() {
return this.img2;
}
public void setImg2(String img2) {
this.img2 = img2;
}
#Column(name = "video_url", length = 65535)
public String getVideoUrl() {
return this.videoUrl;
}
public void setVideoUrl(String videoUrl) {
this.videoUrl = videoUrl;
}
#Column(name = "creater_id")
public Integer getCreaterId() {
return this.createrId;
}
public void setCreaterId(Integer createrId) {
this.createrId = createrId;
}
#Temporal(TemporalType.TIMESTAMP)
#Column(name = "created_date", length = 19)
public Date getCreatedDate() {
return this.createdDate;
}
public void setCreatedDate(Date createdDate) {
this.createdDate = createdDate;
}
#Column(name = "update_id")
public Integer getUpdateId() {
return this.updateId;
}
public void setUpdateId(Integer updateId) {
this.updateId = updateId;
}
#Temporal(TemporalType.TIMESTAMP)
#Column(name = "updated_date", length = 19)
public Date getUpdatedDate() {
return this.updatedDate;
}
public void setUpdatedDate(Date updatedDate) {
this.updatedDate = updatedDate;
}
}

How to avoid duplicate insertion of data into my arraylist?
Use a Set instead.
Also, make sure you are implementing equals and hashcode correctly.

EDITED: It should work now.
public String execute()
{
String bookid = request.getParameter("bid");
Bookdetails book = dao.listBookDetailsById(Integer.parseInt(bookid));
books = (ArrayList) session.get( VisionBooksConstants.USER );
if ( books == null ) books = new ArrayList<Bookdetails>();
boolean already_exists = false;
for ( Bookdetails b : books ) {
if ( b.getID().equals(bookid) ) {
already_exists = true; break;
}
}
if (book != null && !already_exists )
{
books.add(book);
System.out.println("books size"+books.size());
session.put(VisionBooksConstants.USER,books);
}
return SUCCESS;
}