implementato parzialmente la deque

queue/NodeQueue.java

@@ -0,0 +1,106 @@
+package queue;
+
+import exceptions.EmptyQueueException;
+import stack.utility.Node;
+
+import java.awt.image.AreaAveragingScaleFilter;
+
+/**
+ * Created with xgiovio.macbookair.
+ * User: xgiovio
+ * Date: 17/03/14
+ * Time: 14:08
+ */
+public class NodeQueue<E> implements Queue<E> {
+
+
+    @Override
+    public void enqueue(E element) {
+
+            Node<E> temp = new Node<E>(element,null);
+            if (rear == null){
+                rear = temp;
+            }else {
+                rear.setNext(temp);
+                rear = temp;
+            }
+            number_of_elements++;
+            if (number_of_elements == 1){
+                front = rear;
+            }
+
+    }
+
+    @Override
+    public E dequeue() throws EmptyQueueException {
+            if (isEmpty()){
+                throw new EmptyQueueException();
+            }else{
+               Node<E> temp = front;
+               front = front.getNext();
+               number_of_elements--;
+               if (number_of_elements == 0){
+                   rear = front;
+               }
+               return temp.getElement();
+            }
+    }
+
+    @Override
+    public E front() throws EmptyQueueException {
+        if (isEmpty()){
+            throw new EmptyQueueException();
+        } else{
+            return front.getElement();
+        }
+    }
+
+    @Override
+    public boolean isEmpty() {
+        if (number_of_elements == 0){
+            return true;
+        }else{
+            return false;
+        }
+    }
+
+    @Override
+    public boolean isFull() {
+        return false;
+    }
+
+    @Override
+    public int size() {
+        return number_of_elements;
+    }
+
+
+    @Override
+    public String toString() {
+        Node<E> temp;
+        String to_return = "";
+        if (!isEmpty()){
+            for (temp = front;temp != null;temp = temp.getNext()){
+                to_return+=temp.getElement();
+                if (temp.getNext() != null){
+                    to_return+=",";
+                }
+
+            }
+
+        }
+        return to_return;
+
+    }
+
+
+
+
+
+
+    private Node<E> front = null;
+    private Node<E> rear = null;
+    private int number_of_elements = 0;
+
+
+}