Question

All APIs in Hibernate are from 1.4 and are thus not using java generics.

So I wonder how ‘safe’ the following is: (preconditions: name column is of datatype String, or atleast compatible to String)

@SuppressWarnings('unchecked') public List<String> getAll() {     Query q = session.createQuery(         'select name from Customers');     return q.list();     } 

From the Queryi API (org.hibernate.Query.list()) javadoc.

‘Return the query results as a List. If the query contains multiple results pre row, the results are returned in an instance of Object[]. ‘

Answer 1

It’ll be safe as long as you are sure that the query does not ‘contain multiple results per row’. (I’m not familiar with queries, so I am unsure whether it can happen in this case.) If a row does contain multiple results, then when you try to access it, it will throw ClassCastException at runtime because that element will be an Object[] object instead of a String object.