How to create Rows in Database with EJB3.0 Entities - Proble
Hi,
I don't have much experience in writing Entity Java Beans, so if some questions are "dummy-questions", I apologize for that.
Actual state: I have implemented Entity Java Beans with relationships between them. I can deploy them to JBOSS AS and everything is fine. Then, I want to implement a small client to fill the database with some values to check if my Beans are correct.
Problem: I have three Beans, that have relationships.
Entity Flight, Entity FlightSeat and Entity Address
Flight has a OneToMany relationship with FlightSeat and two ManyToOne relationships with Address (for start- and destinationaddress of the flight)
No, I want to create Values in the database with the Entities, but I don't know how I have to conside the relationships. How can I add a Flight row to the database? Do I have to specifiy the start- and destinationaddress, when saving the entity Flight with Entitymanager.persist()?? Maybe you know a good Tutorial where I can see, how it is possible to fill the tables?
Here my Implementation:
Flight.java:
package at.ac.tuwien.inetappl.entity;
import java.io.Serializable;
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.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.persistence.FetchType;
import java.util.Date;
import java.util.Collection;
@Entity
@Table (name="REL_FLIGHT")
public class Flight implements Serializable{
private long flightid;
private String company;
private Date duration;
private Address startaddress;
private Address destinationaddress;
private Collection<FlightSeat> seats;
public Flight() {}
public Flight(String company, Date duration, Address startaddress, Address destinationaddress)
{
this.company=company;
this.duration=duration;
this.startaddress=startaddress;
this.destinationaddress=destinationaddress;
}
@Id @GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="FLIGHT_ID")
public long getId()
{
return this.flightid;
}
public void setId(long flightid)
{
this.flightid = flightid;
}
@Column(name="COMPANY")
public String getCompany()
{
return this.company;
}
public void setCompany(String company)
{
this.company=company;
}
@Column(name="DURATION")
public Date getDuration()
{
return this.duration;
}
public void setDuration(Date duration)
{
this.duration=duration;
}
@ManyToOne (optional=false)
@JoinColumn(name = "START_ADDRESS_ID")
public Address getStartAddress()
{
return this.startaddress;
}
public void setStartAddress(Address startaddress)
{
this.startaddress=startaddress;
}
@ManyToOne (optional=false)
@JoinColumn(name = "DESTINATION_ADDRESS_ID")
public Address getDestinationAddress()
{
return this.destinationaddress;
}
public void setDestinationAddress(Address destinationaddress)
{
this.destinationaddress=destinationaddress;
}
@OneToMany(cascade = CascadeType.ALL, fetch=FetchType.EAGER, mappedBy="flight")
//@JoinColumn(name= "SEAT_ID")
public Collection<FlightSeat> getSeats()
{
return this.seats;
}
public void setSeats(Collection<FlightSeat> seats)
{
this.seats=seats;
}
}
Address.java:
package at.ac.tuwien.inetappl.entity;
import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.Column;
@Entity
@Table (name="REL_ADDRESS")
public class Address implements Serializable{
private String land;
private String city;
private String street;
private int streetnumber;
private int postalcode;
private long addressid;
public Address() {}
public Address (String land, String city, String street,
int streetnumber, int postalcode) {
this.land=land;
this.city=city;
this.street=street;
this.streetnumber=streetnumber;
this.postalcode=postalcode;
}
@Id @GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="ADDRESS_ID")
public long getId()
{
return this.addressid;
}
public void setId(long addressid)
{
this.addressid = addressid;
}
@Column(name="LAND")
public String getLand()
{
return this.land;
}
public void setLand(String land)
{
this.land=land;
}
@Column(name="CITY")
public String getCity()
{
return this.city;
}
public void setCity(String city)
{
this.city=city;
}
@Column(name="STREET")
public String getStreet()
{
return this.street;
}
public void setStreet(String street)
{
this.street=street;
}
@Column(name="STREETNUMBER")
public int getStreetNumber()
{
return this.streetnumber;
}
public void setStreetNumber(int streetnumber)
{
this.streetnumber=streetnumber;
}
@Column(name="POSTALCODE")
public int getPostalCode()
{
return this.postalcode;
}
public void setPostalCode(int postalcode)
{
this.postalcode=postalcode;
}
}
FlightSeat.java
package at.ac.tuwien.inetappl.entity;
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Entity;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;
@Entity
@Table (name="REL_FLIGHTSEAT")
public class FlightSeat implements Serializable {
private long seatid;
private String category;
private int price;
private boolean available;
private Flight flight;
public FlightSeat() {}
public FlightSeat(String category, int price, boolean available)
{
this.category=category;
this.price=price;
this.available=available;
}
@Id @GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="SEAT_ID")
public long getId()
{
return this.seatid;
}
public void setId(long seatid)
{
this.seatid = seatid;
}
@Column(name="CATEGORY")
public String getCategory()
{
return this.category;
}
public void setCategory(String category)
{
this.category=category;
}
@Column(name="PRICE")
public int getPrice()
{
return this.price;
}
public void setPrice(int price)
{
this.price=price;
}
@Column(name="AVAILABLE")
public boolean getAvailability()
{
return this.available;
}
public void setAvailability(boolean available)
{
this.available=available;
}
@ManyToOne()
@JoinColumn(name="FLIGHT_ID")
public Flight getFlight()
{
return this.flight;
}
public void setFlight(Flight flight)
{
this.flight=flight;
}
}
FlightBean.java - implementing business methods
package at.ac.tuwien.inetappl.bean;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.ejb.Remote;
import at.ac.tuwien.inetappl.entity.Flight;
import at.ac.tuwien.inetappl.entity.Address;
import at.ac.tuwien.inetappl.entity.FlightSeat;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import java.io.Serializable;
import javax.persistence.Query;
@Stateless
@Remote(FlightInterface.class)
public class FlightBean implements FlightInterface, java.io.Serializable {
//private Collection<Flight> flight;
@PersistenceContext
protected EntityManager em;
/* CRUD METHODS FOR FLIGHT */
/* CREATE FLIGHT */
public void createFlight(String company, Date duration, Address start, Address dest)
{
Flight flight = new Flight();
flight.setCompany(company);
flight.setDuration(duration);
flight.setStartAddress(start);
flight.setDestinationAddress(dest);
em.persist(flight);
}
public void updateFlight(Flight flight)
{
em.persist(flight);
}
/* DELETE FLIGHT*/
public void deleteFlight(long id)
{
Query q = em.createQuery("DELETE FROM FLIGHT f WHERE f.FLIGHT_ID = :id");
q.setParameter ("id", new Long(id));
}
/* SEARCH METHODS FOR FLIGHT */
public Collection<Flight> getFlights()
{
return em.createQuery("from FLIGHT f").getResultList();
}
public Flight getFlight(long id) {
Flight flight = em.find(Flight.class, new Long(id));
return flight;
}
public String getCompany(long id) {
Flight flight = em.find(Flight.class, new Long(id));
String company = flight.getCompany();
return company;
}
}
Thanks to all!! I hope, i can find help here!
Greetings,
redbaron
