Removing the “first” object from a Set

Question

Under certain situations, I need to evict the oldest element in a Java Set. The set is implemented using a LinkedHashSet, which makes this simple: just get rid of t

Answer 1

LinkedHashSet is a wrapper for LinkedHashMap which supports a simple "remove oldest" policy. To use it as a Set you can do

Set set = Collections.newSetFromMap(new LinkedHashMap(){
    protected boolean removeEldestEntry(Map.Entry eldest) {
        return size() > MAX_ENTRIES;
    }
});