How can I create a memory leak in Java?

Question

I just had an interview, and I was asked to create a memory leak with Java.

Needless to say, I felt pretty dumb having no clue on how to eve

Answer 1

Create a static Map and keep adding hard references to it. Those will never be garbage collected.

public class Leaker {
    private static final Map CACHE = new HashMap();

    // Keep adding until failure.
    public static void addToCache(String key, Object value) { Leaker.CACHE.put(key, value); }
}