Is there a fixed sized queue which removes excessive elements?

Yes, Two

From my own duplicate question with this correct answer, I learned of two:

• EvictingQueue in Google Guava
• CircularFifoQueue in Apache Commons

---

I made productive use of the Guava EvictingQueue, worked well.

To instantiate an EvictingQueue call the static factory method create and specify your maximum size.

EvictingQueue< Person > people = com.google.common.collect.EvictingQueue.create( 100 ) ;  // Set maximum size to 100. 

Actually the LinkedHashMap does exactly what you want. You need to override the removeEldestEntry method.

Example for a queue with max 10 elements:

  queue = new LinkedHashMap<Integer, String>()
  {
     @Override
     protected boolean removeEldestEntry(Map.Entry<Integer, String> eldest)
     {
        return this.size() > 10;   
     }
  };

If the "removeEldestEntry" returns true, the eldest entry is removed from the map.

I just implemented a fixed size queue this way:

public class LimitedSizeQueue<K> extends ArrayList<K> {

    private int maxSize;

    public LimitedSizeQueue(int size){
        this.maxSize = size;
    }

    public boolean add(K k){
        boolean r = super.add(k);
        if (size() > maxSize){
            removeRange(0, size() - maxSize);
        }
        return r;
    }

    public K getYoungest() {
        return get(size() - 1);
    }

    public K getOldest() {
        return get(0);
    }
}