How to implement a generic method to get data from database with Hibernate?

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I have generic method for add, update and delete entities. But I also want to use generics for retrieving data.

Here is my methods to get data:

public static List<ClassA> getAllClassAData() {
    Session session = HibernateUtil.getSessionFactory().openSession();
    Criteria criteria = session.createCriteria(ClassA.class);
    return criteria.list();
}

public static List<ClassB> getAllClassBData() {
    Session session = HibernateUtil.getSessionFactory().openSession();
    Criteria criteria = session.createCriteria(ClassB.class);
    return criteria.list();
}

public static List<ClassC> getAllClassCData() {
    Session session = HibernateUtil.getSessionFactory().openSession();
    Criteria criteria = session.createCriteria(ClassC.class);
    return criteria.list();
}

I tried to make something like this:

public static <T> List<T> getAllData() {
    Session session = HibernateUtil.getSessionFactory().openSession();
    Criteria criteria = session.createCriteria(???.class); //Here is where I'm stuck
    return criteria.list();
}

And I stuck with passing the class as arg for criteria creation:

 Criteria criteria = session.createCriteria(Generic.class);

How can I make JVM know what class I'm trying to pass during criteria creation?

4 Answers
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