How to clone a BlockingQueue in Java?

Question

In my Java Application I have

BlockingQueue<HashMap<Integer, double[]>> q

How do I clone it?

Answer 1

1. Basic copy : copy of the Queue

   BlockingQueue<HashMap<Integer, double[]>> q; // = ...
   BlockingQueue<HashMap<Integer, double[]>> copy = new LinkedBlockingDeque<>(q);
   

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2. Deep copy : copy of the Queue and the Map's

   BlockingQueue<HashMap<Integer, double[]>> q; // = ...
   BlockingQueue<HashMap<Integer, double[]>> copy = new LinkedBlockingDeque<>();//or other
   
   for(HashMap<Integer, double[]> map : q){
       copy.add(new HashMap<>(map));
   }
   

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3. Very deep copy : copy of the Queue, the Map's and the double[]'s

   BlockingQueue<HashMap<Integer, double[]>> q; // = ...
   BlockingQueue<HashMap<Integer, double[]>> copy = new LinkedBlockingDeque<>();//or other
   
   for(HashMap<Integer, double[]> map : q){
       Map<Integer, double[]> mapCopy = new HashMap<>();
       for(Map.Entry<Integer, double[]> entry : map.entrySet()){
           double[] array = entry.getValue();
           mapCopy.put(entry.getKey(), Arrays.copyOf(array, array.length));
       }
       copy.add(mapCopy);
   }