（JAVA EE）方法不工作不拋出任何錯誤

Question

我深化發展使用Java EE，EJB & JPA（EclipseLink的）航空公司管理Web應用程序

我有，當我打電話的方法的麻煩在servlet的服務層中：該方法沒有做任何預期的事情而沒有任何錯誤。

該方法是AddPassengerToFlight，在那裏我試圖添加一個乘客到乘客列表，我在具有ManyToMany關係的飛行實體中。

這是priject的結構。

這是飛行和乘客實體whitout getter和setter：

飛行：

public class Flight implements Serializable { 


    @Id 
    @GeneratedValue(strategy = GenerationType.AUTO) 
    private Integer   id; 

    @Enumerated(EnumType.STRING) 
    private Cities   depart; 

    @Enumerated(EnumType.STRING) 
    private Cities   destination; 

    private String   prix; 

    @Temporal(TemporalType.TIMESTAMP) 
    private Date   date; 

    @ManyToMany(cascade = { CascadeType.MERGE, CascadeType.PERSIST, CascadeType.REFRESH }) 
    @JoinTable(name = "f_p_join", joinColumns = @JoinColumn(name = "flight_fk"), inverseJoinColumns = @JoinColumn(name = "passenger_fk")) 
    private List<Passenger> passengers; 

    @OneToOne() 
    @JoinColumn(name = "airplane_fk") 
    private Plane   airplane; 

    @OneToOne() 
    @JoinColumn(name = "pilot_fk") 
    private Pilot   pilot; 
} 

乘客：

public class Passenger implements Serializable { 


    @Id 
    @GeneratedValue(strategy = GenerationType.AUTO) 
    private Integer  id; 

    private String  nom; 

    private String  prenom; 

    private String  adresse; 

    private String  telephone; 

    private String  email; 

    @Enumerated(EnumType.STRING) 
    private FlightClass flightClass; 

    @ManyToMany(mappedBy = "passengers") 
    private List<Flight> flights; 
} 

的PassenerService其中i有方法：

public class PassengerService { 

    private static final String CHAMP_FLIGHT_ID = "flightId"; 
    private static final String CHAMP_PASSENGER_ID = "passengerId"; 

    private String    resultat; 
    private Map<String, String> erreurs   = new HashMap<String, String>(); 
    private PassengerDao  passengerDao; 
    private FlightDao   flightDao; 
    private PilotDao   pilotDao; 
    private PlaneDao   planeDao; 

    public Map<String, String> getErreurs() { 
     return erreurs; 
    } 

    public String getResultat() { 
     return resultat; 
    } 

    public PassengerService(PassengerDao passengerDao, FlightDao flightDao, PilotDao pilotDao, PlaneDao planeDao) { 
     this.passengerDao = passengerDao; 
     this.flightDao = flightDao; 
     this.pilotDao = pilotDao; 
     this.planeDao = planeDao; 
    } 

    public Passenger createPassenger(HttpServletRequest request) { 
     //The createPassenger code 
    } 

    public List<Passenger> getAllPassengers() { 
     //The getAllPassengers Code 
    } 

    public void AddPassengerToFlight(HttpServletRequest request) { 
     FlightService flightService = new FlightService(flightDao, planeDao, pilotDao); 

     String passengerId = request.getParameter(CHAMP_PASSENGER_ID); 
     String flightId = request.getParameter(CHAMP_FLIGHT_ID); 

     Passenger passenger = getPassengerById(passengerId); 
     Flight flight = flightService.getFlightById(flightId); 

     List<Passenger> pList = flight.getPassengers(); 
     pList.add(passenger); 
     flight.setPassengers(pList); 

     passenger.getFlights().add(flight); 

    } 

    public Passenger getPassengerById(String passengerId) { 
     Passenger passenger = passengerDao.getPassengerById(passengerId); 
     return passenger; 
    } 

    public void removePassenger(Passenger passenger) { 
     //The removePassenger code 

    } 


} 

這是servlet AddPassengerToFlight

@WebServlet("/AddPassengerToFlight") 
public class AddPassengerToFlight extends HttpServlet { 

    private static final String VUE_REDIRECT  = "/airline/PassengerList"; 

    private static final long serialVersionUID = 1L; 

    @EJB 
    FlightDao     flightDao; 

    @EJB 
    PilotDao     pilotDao; 

    @EJB 
    PlaneDao     planeDao; 

    @EJB 
    PassengerDao    passengerDao; 


    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, 
      IOException { 
     FlightService flightService = new FlightService(flightDao, planeDao, pilotDao); 
     PassengerService passengerService = new PassengerService(passengerDao, flightDao, pilotDao, planeDao); 

     List<Flight> flights = flightService.getAllFlights(); 
     List<Passenger> passengers = passengerService.getAllPassengers(); 
     request.setAttribute("flights", flights); 
     request.setAttribute("passengers", passengers); 
     this.getServletContext().getRequestDispatcher(VUE).forward(request, response); 
    } 


    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, 
      IOException { 
     PassengerService passengerService = new PassengerService(passengerDao, flightDao, pilotDao, planeDao); 

     passengerService.AddPassengerToFlight(request); 
     response.sendRedirect(VUE_REDIRECT); 

    } 

} 

這是形式AddPassengerToFlight（JSP文件）

<div class="container"> 
     <h2>Adding Passenger To Flight</h2> 
     <br/><br/> 
     <form method="POST" action="AddPassengerToFlight"> 
      <div class="form-group"> 
       <h4>Flight :</h4> 
       <select name="flightId" class="selectpicker" data-live-search="true" data-width="100%"> 
        <c:forEach items="${flights}" var="flight"> 
         <option value="${flight.id}"> 
          FROM <c:out value="${flight.depart}" /> TO <c:out value="${flight.destination}" /> AT <c:out value="${flight.date}" /> 
         </option> 
        </c:forEach> 
       </select> 
      </div> 


      <div class="form-group"> 
       <h4>Passenger :</h4> 
       <select name="passengerId" class="selectpicker" data-live-search="true" data-width="100%"> 
        <c:forEach items="${passengers}" var="passenger"> 
         <option value="${passenger.id}"><c:out value="${passenger.nom}" /></option> 
        </c:forEach> 
       </select> 
      </div> 

      <button type="submit" class="btn btn-default">Submit</button> 

     </form> 
    </div> 

當我點擊重定向到PassengerList的AddPassengerToFlight IM的按鈕提交，但什麼也沒有發生兩個實體（飛行和乘客）之間，我沒有錯誤。

任何人都可以弄清楚我在這裏做錯了嗎？

Answer 1

我相信你的問題在於你的PassengerService類是一個普通的JAVA類（我解釋，不是一個EJB服務）......因此，當你在該類的Passanger和Flight之間建立關聯時，沒有JTA事務正在運行，您的實體處於分離模式;所以，它們的任何更改都不會在數據庫中持久化。

您可以快速嘗試一下，看看我是否正確...使您的服務成爲EJB類，並通過@EJB註釋注入所需的DAO，從Servlet注入新的EJB，然後調用方法：AddPassengerToFlight(HttpServletRequest request) .. 。