How to remove SuppressWarnings ("unchecked")

Question

Is there any way I can change this code so that I can remove the unverified warning

ArrayList<String> keys = new ArrayList<String>();
// do some stuff then
// save keys in session
HttpServletRequest request = getThreadLocalRequest();
HttpSession session = request.getSession(true);
session.setAttribute(uuid, keys);

// get keys from session sometime later
@SuppressWarnings("unchecked")
ArrayList<String> keys = (ArrayList<String>) session.getAttribute(uuid);

Answer 1

You can not. session.getAttribute()unsafe.

You can create a wrapper method, so you only have @SuppressWarningsone place:

public final class SessionUtils {
    @SuppressWarnings("unchecked")
    public static <T> T getSessionAttribute(HttpSession session, String name) {
        return (T) session.getAttribute(name);
    }
}

Then you can use without warning:

List<String> keys = SessionUtils.getAttribute(session, uuid);

Answer 2

Well, you need to choose between:

• Warning for source type
• Unverified Conversion Warning
• Annotation to remove a warning for the source type
• Annotation to remove a warning for an unverified conversion

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