Question

我正在玩交易。

我将JPA配置为处理我的实体，并希望将它们保存在数据库中。问题是，当我的程序抛出runtimeException时，CMT不会回滚。

这个＆＃34;容器事物背后的想法＆＃34;很难理解，记录很差。

@transactional托管交易，纯CDI Interceptor托管交易和Bean托管交易都像魅力一样。

以下是我编码的内容：这是一个简单的电影演示＆＃34;。你想看两部带X座位的电影。座位有限。如果电影中没有足够的席位，则不应该有交易（ACID和东西）

在我的buyTicketsBoundary课程中：

起初我告诉我的班级我们正在使用CMT：

@Named("buchungBoundry")
@RequestScoped
@TransactionManagement(TransactionManagementType.CONTAINER)
public class BuchungBoundry {

@EJB
private BuchungVerwaltung buyTicketsController;
@EJB
private KundenVerwaltung customerController;
@EJB
private SaalVerwaltung roomController;
@EJB
private MovieVerwaltung movieController;



private int ticketsForMovie1; //this is how many tickets we want to buy
private int ticketsForMovie2;

public BuchungBoundry() {
}

@TransactionAttribute(TransactionAttributeType.REQUIRED)
public void buyTickets() throws MyException {


    int numberOfSeantsInRoom1=roomController.getSaal(4).getAnzahlPlaetze();
    int numberOfSeantsInRoom2=roomController.getSaal(5).getAnzahlPlaetze();

    int alreadyBoughtSeatsIn1=buyTicketsController.getBelegtePlatzeNachSaal(4);
    int alreadyBoughtSeatsIn2=buyTicketsController.getBelegtePlatzeNachSaal(5);

    int availableSeats1 = numberOfSeantsInRoom1 - alreadyBoughtSeatsIn1;
    int availableSeats2 = numberOfSeantsInRoom2 - alreadyBoughtSeatsIn2;


    System.out.println("Saal A: ("+alreadyBoughtSeatsIn1+"/"+numberOfSeantsInRoom1+") want to buy :" + ticketsForMovie1);
    System.out.println("Saal B: ("+alreadyBoughtSeatsIn2+"/"+numberOfSeantsInRoom2+") want to buy :" + ticketsForMovie2);

    try {
        if (ticketsForMovie1 <= availableSeats1) {
        buyTicketsController.erstelleBuchung(customerController.getKunde(1),
                movieController.getMovie(7),
                roomController.getSaal(4),
                ticketsForMovie1);
        } else {
            throw new MyException("ERROR: no room for "
                    + ticketsForMovie1 + " person! "
                    +alreadyBoughtSeatsIn1);
        }
        if (ticketsForMovie2 <= availableSeats2) {
            buyTicketsController.erstelleBuchung(customerController.getKunde(1),
                    movieController.getMovie(8),
                    roomController.getSaal(5),
                    ticketsForMovie2);
        } else {
            throw new MyException("ERROR: no room for "
                    + ticketsForMovie2 + " person! "
                    +alreadyBoughtSeatsIn2);
        }

    } catch (MyException | IllegalStateException | SecurityException ex) {
        Logger.getLogger(BuchungBoundry.class.getName()).log(Level.SEVERE, null, ex);
    }
}

我的例外：

@ApplicationException(rollback=true)
public class MyException extends RuntimeException{
    public MyException()  {

    }

    public MyException(String s) {
        System.out.println(""+s);
    }
}

通过JPA在数据库中编写Bought票证的Controller类：

@Stateless
public class BuchungVerwaltung implements Serializable {

@PersistenceContext(unitName = "kbse-JTA")
private EntityManager em;

public BuchungVerwaltung() {
}

public void erstelleBuchung(Kunde k, Movie movie, Saal saal, int anzahlPlaetze) {
    Buchung b = new Buchung(k, movie, saal, anzahlPlaetze);
    em.persist(b);
}

public int getBelegtePlatzeNachSaal(int id) {
    try {
        Query query = em.createNativeQuery("select sum(b.ANZAHL) from SAAL s,BUCHUNG b where s.SAAL_ID = b.SAAL_SAAL_ID and s.SAAL_ID=?");
        query.setParameter(1, id);
        return (int) query.getSingleResult();
    } catch (Exception e) {
        return 0;
    }
}

public List<Buchung> getAlleBuchungen() {
    TypedQuery<Buchung> query = em.createQuery("select s from Buchung s", Buchung.class);
    return query.getResultList();
}
}

问题是，当此类到达第一部电影的em.persist状态，而第二部电影抛出异常时，数据库无法回滚。

我想如果抛出了RuntimeException，那么Container就会回滚

我能做些什么才能让它发挥作用？

Plase告诉我，如果有什么不清楚的话

Answer 1

我做了所有的核心，唯一的错误是抓住了＃34; myException＆＃34;

} catch (MyException | IllegalStateException | SecurityException ex) {

} catch ( IllegalStateException | SecurityException ex) {

现在好了，容器可以按照它应该回滚

容器管理事务无法回滚

1 个答案: