Question

How can I return a list of Question objects in XML or JSON?

@Path("all")
@GET
public List<Question> getAllQuestions() {
    return questionDAO.getAllQuestions();
}

I get this exception:

SEVERE: Mapped exception to response: 500 (Internal Server Error)
javax.ws.rs.WebApplicationException:
com.sun.jersey.api.MessageException: A message body writer for Java
class java.util.Vector, and Java type
java.util.List, and MIME media
type application/octet-stream was not found

Answer 1

Try:

@Path("all")
@GET
public ArrayList<Question> getAllQuestions() {
    return (ArrayList<Question>)questionDAO.getAllQuestions();
}

If your goal is to return a list of item you can use:

@Path("all")
@GET
public Question[] getAllQuestions() {
    return questionDAO.getAllQuestions().toArray(new Question[]{});
}

Edit
Added original answer above