How to avoid type safety warnings with Hibernate HQL results?

Using @SuppressWarnings everywhere, as suggested, is a good way to do it, though it does involve a bit of finger typing each time you call q.list().

There are two other techniques I'd suggest:

Write a cast-helper

Simply refactor all your @SuppressWarnings into one place:

List<Cat> cats = MyHibernateUtils.listAndCast(q);

...

public static <T> List<T> listAndCast(Query q) {
    @SuppressWarnings("unchecked")
    List list = q.list();
    return list;
}

Prevent Eclipse from generating warnings for unavoidable problems

In Eclipse, go to Window>Preferences>Java>Compiler>Errors/Warnings and under Generic type, select the checkbox Ignore unavoidable generic type problems due to raw APIs

This will turn off unnecessary warnings for similar problems like the one described above which are unavoidable.

Some comments:

• I chose to pass in the Query instead of the result of q.list() because that way this "cheating" method can only be used to cheat with Hibernate, and not for cheating any List in general.
• You could add similar methods for .iterate() etc.

It is been a long time since the question was asked but I hope my answer might be helpful to someone like me.

If you take a look at javax.persistence api docs, you will see that some new methods have been added there since Java Persistence 2.0. One of them is createQuery(String, Class<T>) which returns TypedQuery<T>. You can use TypedQuery just as you did it with Query with that small difference that all operations are type safe now.

So, just change your code to smth like this:

Query q = sess.createQuery("from Cat cat", Cat.class);
List<Cat> cats = q.list();

And you are all set.

We use @SuppressWarnings("unchecked") as well, but we most often try to use it only on the declaration of the variable, not on the method as a whole:

public List<Cat> findAll() {
    Query q = sess.createQuery("from Cat cat");
    @SuppressWarnings("unchecked")
    List<Cat> cats = q.list();
    return cats;
}

Try to use TypedQuery instead of Query. For example instead of this:-

Query q = sess.createQuery("from Cat cat", Cat.class);
List<Cat> cats = q.list();

Use this:-

TypedQuery<Cat> q1 = sess.createQuery("from Cat cat", Cat.class);
List<Cat> cats = q1.list();

In our code we annotate the calling methods with:

@SuppressWarnings("unchecked")

I know it seems like a hack, but a co-developer checked recently and found that was all we could do.