How can I implement
class CaseInsensitiveConcurrentMap<V> implements ConcurrentMap<String , V>
which works just like ConcurrentHashMap<String , V> except that the keys are compared case-insensitively? The keys should not be converted to lowercase or uppercase.
Note that Collections.synchronizedMap(new TreeMap<String, new MyCaseInsensitiveComparator()) is no solution as it allows no concurrency and misses the additional methods.
Creating a String-like class with case-insensitive equals and hashCode is no option either, since the map has to be passed to methods expecting strings as keys.