I want to construct a quick LRU cache. Is this kind of solution is a good way to do this ? And what about the synchronization ?
There’s a protected method called removeEldestEntry. This method is called when items are being added to the map. The default implementation just returns false. But i can subclass LinkedHashMap and override this method to check whether a maximum size has been reached, then just return true. The LinkedHashMap will find the oldest entry via the linked list and boot it before adding a new entry.
public class MyLRUMap<K,V> extends LinkedHashMap<K,V> {
private int maxCapacity;
public MyLRUMap(int initialCapacity, float loadFactor, int maxCapacity) {
super(initialCapacity, loadFactor, true);
this.maxCapacity = maxCapacity;
}
@Override
protected boolean removeEldestEntry(Entry<K,V> eldest) {
return size() >= this.maxCapacity;
}
}
Thanks
That is the recommended way to do it although it might be best to do size() > this.maxCapacity
instead of >=