Java：Hibernate太慢了

Question

我正在研究一个swing应用程序，因为它的性能来处理我选择Hibernate的数据。现在我做了80％的工作。我发现应用程序太慢了，就像永远在等待。我用google搜索它，发现如果有很多数据，Hibernate不是最好的选择。我不知道那个问题是我的数据库很复杂很多关联，连接，设置...... 我没有时间重新开始！请帮忙

这里是一段代码，这是我检索数据的方法，每个实体都有类似的类

public class CoursCrud {
SessionFactory sessionFactory = HibernateUtil.getSessionFactory();  
Session session ;
 public ArrayList<Object> findCoursByCoursId( int id){
    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findCoursByCoursId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public ArrayList<Object> findLastCours(){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findLastCours");
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public ArrayList<Object> findAllCours(){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findAllCours");
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public ArrayList<Object> findProfByCoursId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findProfByCoursId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}

  public ArrayList<Object> findGroupeByCoursId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findGroupeByCoursId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public ArrayList<Object> findGroupeByCreneauId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findGroupeByCoursId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public ArrayList<Object> findSalleByCreneauId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findSalleByCreneauId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public ArrayList<Object> findProfByCreneauId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findProfByCreneauId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public ArrayList<Object> findCreneauFromCoursByCreneauId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findCreneauFromCoursByCreneauId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();

    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public ArrayList<Object> findCoursByCreneauId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findCoursByCreneauId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}

  public ArrayList<Object> findSalleByCoursId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findSalleByCoursId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public ArrayList<Object> findCreneauByCoursId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findCreneauByCoursId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}

public   ArrayList<Object> findCoursByGroupeId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findCoursByGroupeId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;
}
public   ArrayList<Object> findCoursBySalleId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findCoursBySalleId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;
}
public   ArrayList<Object> findProfBySalleId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findProfBySalleId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;
}


  public int findIndex(int id){
    CoursCrud C= new CoursCrud();
    ArrayList<Object> cours =C.findAllCours(); 
    int i=0;
    for(Object cu: cours){
        i++;
        if(((Cours) cu).getId() == id){
            break;
        }
    }
    return --i;
}
public void createData( Object p){
    session = HibernateUtil.getSessionFactory().openSession();
    Transaction transaction = null;
    try {
        transaction = session.beginTransaction();
        session.save(p);  
        transaction.commit();  
    } catch (HibernateException e) {
        transaction.rollback();
        e.printStackTrace();
    } finally {
        session.close();
    }  
}
public void updateData( Object p){

    session = sessionFactory.openSession();  
    session.beginTransaction();  

    session.update(p);  
    session.getTransaction().commit();  

    session.close();
}

public void CoursEmpty(){  
    CoursCrud C= new CoursCrud();
    List<Object> cc = C.findAllCours();
    for(Object c: cc){
        C.deleteCoursByCoursId(((Cours)c).getId());
    }
}
public void deleteCoursByCoursId(int id){
    session = HibernateUtil.getSessionFactory().openSession();
    CoursCrud C= new CoursCrud();
    Transaction transaction = null;
    try {
        transaction = session.beginTransaction();     
        Cours c = (Cours) C.findCoursByCoursId(id).get(0);
        session.delete(c);
        transaction.commit();  
    } catch (HibernateException e) {
        transaction.rollback();
        e.printStackTrace();
    } finally {
        session.close();
    }   
}

public void deleteCoursCreneauByCoursId(int id){
    session = HibernateUtil.getSessionFactory().openSession();
    Transaction transaction = null;
    try {
        transaction = session.beginTransaction();     
        Query Q = session.getNamedQuery("deleteCoursCreneauByCoursId");
        Q.setLong("id", id).executeUpdate();
        transaction.commit();  
    } catch (HibernateException e) {
        transaction.rollback();
        e.printStackTrace();
        System.out.println("Not succ !! \n");
    } finally {
        session.close();
    }   
}

  public ArrayList<Object> findCreneauIndisponibiliteByCoursId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findCreneauIndisponibiliteByCoursId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public ArrayList<Object> findCoursIndisponibleByCreneauId(int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findCoursIndisponibleByCreneauId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public ArrayList<Object> findCoursByClassCoursId( int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findCoursByClassCoursId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public void deleteCoursByClassCours(int id){
    CoursCrud C= new CoursCrud();
    for(Object o: C.findCoursByClassCoursId(id)){
        C.deleteCoursSeanceByCoursId(((Cours)o).getId());
        C.deleteCoursCreneauByCoursId(((Cours)o).getId());
        C.deleteCoursByCoursId(((Cours)o).getId());
    }
}
  public ArrayList<Object> findGroupeByClassCoursId( int id){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findGroupeByClassCoursId");
    Q.setLong("id", id);
    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public ArrayList<Integer> findIndexGroupebyClassCours(int id){
    CoursCrud C= new CoursCrud();
    GroupeCrud Gc= new GroupeCrud();
    ArrayList<Object> groupeSelectedList= C.findGroupeByClassCoursId(id);
    ArrayList<Object> groupeList= Gc.findAllGroupe();
    ArrayList<Integer> indexSelectedList= new ArrayList<Integer>();

    Alert a= new Alert();
    for(Object m: groupeList){
        for(Object ms: groupeSelectedList){
            if(((Groupe) m).getId() == ((Groupe) ms).getId() ){
                indexSelectedList.add(groupeList.indexOf(m));
            }
        }
    }
    return indexSelectedList;
}
  public ArrayList<Integer> findIndexSeancebyClassCours(int id){
    CoursCrud C= new CoursCrud();
    SeanceCrud sC=new SeanceCrud();
    ArrayList<Seance> SeanceSelectedList = new ArrayList<Seance>();
    for(Object o: C.findCoursByClassCoursId(id)){
        for(Object v: sC.findSeanceByCoursId(((Cours)o).getId())){
            SeanceSelectedList.add((Seance)v);
        }
    }

    ArrayList<Object> seanceList= sC.findAllSeance();
    ArrayList<Integer> indexSelectedList= new ArrayList<Integer>();

    Alert a= new Alert();
    for(Object m: seanceList){
        for(Seance ms: SeanceSelectedList){
            if(((Seance) m).getId() == ms.getId() ){
                indexSelectedList.add(seanceList.indexOf(m));
            }
        }
    }
    return indexSelectedList;
}
public void deleteCoursSeanceByCoursId(int id){
    CoursCrud C= new CoursCrud();
    session = HibernateUtil.getSessionFactory().openSession();
    Transaction transaction = null;
    try {
        transaction = session.beginTransaction();     
        Cours c = (Cours) C.findCoursByCoursId(id).get(0);
        c.getCoursSeance().clear();
        session.update(c);
        transaction.commit();  
    } catch (HibernateException e) {
        transaction.rollback();
        e.printStackTrace();
    } finally {
        session.close();
    }   
}
  public ArrayList<Integer> findIndexIndisponibilitebyCoursId(int id){
    CoursCrud C= new CoursCrud();
    CreneauCrud cC= new CreneauCrud();
    ArrayList<Object> IndispoSelectedList= C.findCreneauIndisponibiliteByCoursId(id);
    ArrayList<Object> creneauList= cC.findAllCreneau();
    ArrayList<Integer> indexindispoSelectedList= new ArrayList<Integer>();

    Alert a= new Alert();
    for(Object m: creneauList){
        for(Object ms: IndispoSelectedList){
            if(((Creneau) m).getId() == ((Creneau) ms).getId() ){
                indexindispoSelectedList.add(creneauList.indexOf(m));
            }
        }
    }
    return indexindispoSelectedList;
}
  public ArrayList<Object> findCoursIndisponibleByCreneauIdAndCoursId(int idCreneau, int idCours){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findCoursIndisponibleByCreneauIdAndCoursId");
    Q.setLong("idCours", idCours);
    Q.setLong("idCreneau", idCreneau);

    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}
  public ArrayList<Object> findCoursByCreneauIdAndGroupeId(int idCreneau, int idGroupe){

    session = sessionFactory.openSession();  
    Query Q = session.getNamedQuery("findCoursByCreneauIdAndGroupeId");
    Q.setLong("idGroupe", idGroupe);
    Q.setLong("idCreneau", idCreneau);

    List<Object> objet = Q.list();
    session.close(); 
    return (ArrayList<Object>) objet;   
}

Answer 1

也许你试着缩小究竟是什么问题。您的问题可以通过适当的索引等来修复。也许可以提供更多信息。

通常，DB中最慢的部分是数据库连接创建。你在使用DB Pooling吗？

Answer 2

不，绝对不是这样。 hibernate是最好的ORM实现之一。你应该找出你的查询，数据库索引和其他优化。如果数据库，大多数应用程序的最大瓶颈。 如果你看到，hibernate内部使用jdbc并触发SQL查询。它大大减少了你的工作，并提供了非常具体的实现和接口。 请提供更多描述你的问题来解释为什么你觉得hibernate是罪魁祸首而不是别的什么。

Answer 3

你提到数据库实体之间存在复杂的关系，如果你没有，你可能想查看Hibernate“延迟加载”。

延迟加载控制相关实体何时以及如何加载到内存，在许多情况下，它可以带来巨大的性能提升。

Answer 4

您是否返回大型数据集然后使用Java将其过滤为少量记录？我以前见过它。通过网络传输大量数据只是丢弃大部分数据是一个常见的错误。