Question

<hibernate-configuration>
  <session-factory>
    <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
    <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/PP</property>
    <property name="hibernate.connection.username">root</property>
    <property name="hibernate.connection.password"></property>
    <property name="hibernate.show_sql">true</property>
    <property name="hibernate.current_session_context_class">thread</property>
    <property name="hibernate.query.factory_class">org.hibernate.hql.classic.ClassicQueryTranslatorFactory</property>
  </session-factory>
</hibernate-configuration>

HibernateSession.java

public class HibernateSession {

    private static final SessionFactory sessionFactory;

    static {
        try {

            sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
        } catch ( Throwable ex ) {
            // Log the exception.
            System.err.println("Initial SessionFactory creation failed." + ex);
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static SessionFactory getSessionFactory()
      {
        return sessionFactory;
      }
}

用于执行问题的DataFetcher.java

 public class DataFetcher {

        Session session;

        public DataFetcher()
          {
            session = HibernateSession.getSessionFactory().getCurrentSession();
          }

        public void Save(Marki m)
          {
            org.hibernate.Transaction tx = session.beginTransaction();
            session.save(m);
            session.getTransaction().commit();

          }
    }

ManagedBean(name="dodaj")
@ViewScoped
public class DodajOferte implements Serializable {

    private Marki marka;

    public DodajOferte()
      {

        marka = new Marki();
      }

    public String Dodaj()
      {

        DataFetcher f = new DataFetcher();

        try {
            f.Save(marka);
        } catch ( HibernateException ex ) {
            System.out.println(ex.getMessage().toString());

            FacesMessage message = new FacesMessage("err");
            FacesContext context = FacesContext.getCurrentInstance();
            context.addMessage(null, message);
            return null;
        }
        return null;

      }

    public Marki getMarka()
      {
        return marka;
      }

    public void setMarka(Marki marka)
      {
        this.marka = marka;
      }
}

如何正确配置Hibernate？每次交易我都会遇到almogs的问题！在这种情况下，我得到“INFO：非法尝试将集合与两个打开的会话相关联”。当我change session.save(m); to session.merge(m);时，只要我在同一页面上，它就会起作用。当我更改页面，然后返回它，我有很多例外。

Answer 1

不要将会话对象与DataFetcher一起存储。那不是个好主意。每个会话都绑定到绑定它的线程的事务。我不确定这个代码是否在容器中运行，但如果是这样的话，hibernate会尝试使用范围内的事务管理器，而你的代码会让人感到困惑。将您的代码更改为以下内容，看看是否会发生任何变化。

public class DataFetcher {



    public void Save(Marki m)
      {
        Session session = HibernateSession.getSessionFactory().getCurrentSession();
        org.hibernate.Transaction tx = session.beginTransaction();
        session.save(m);
        session.getTransaction().commit();

      }
}

public void Save(Marki m) { Session session = HibernateSession.getSessionFactory().getCurrentSession(); org.hibernate.Transaction tx = session.beginTransaction(); session.save(m); session.getTransaction().commit(); } }

如何正确配置Hibernate

1 个答案: