Implementata completamente la deque

deque/NodeDeque.java

@@ -1,5 +1,6 @@
 package deque;
 
+import deque.utility.DLNode;
 import exceptions.EmptyDequeException;
 
 /**
@@ -10,43 +11,113 @@ import exceptions.EmptyDequeException;
  */
 public class NodeDeque<E> implements Deque <E>  {
 
+    public NodeDeque(){
+        header.setNext(trailer);
+        trailer.setPrev(header);
+    }
+
     @Override
     public int size() {
-        return 0;
+        return nelements;
     }
 
     @Override
     public boolean isEmpty() {
-        return false;
+        if (nelements == 0){
+            return true;
+        } else{
+            return  false;
+        }
     }
 
     @Override
     public E getFirst() throws EmptyDequeException {
-        return null;
+        if (isEmpty()){
+            throw new EmptyDequeException();
+        } else {
+            return header.getNext().getElement();
+        }
     }
 
     @Override
     public E getLast() throws EmptyDequeException {
-        return null;
+        if (isEmpty()){
+            throw new EmptyDequeException();
+        } else {
+            return trailer.getPrev().getElement();
+        }
     }
 
     @Override
     public void addFirst(E element) {
+        DLNode<E> temp = new DLNode<E>(element);
+        temp.setNext(header.getNext());
+        temp.getNext().setPrev(temp);
+        header.setNext(temp);
+        temp.setPrev(header);
+        nelements++;
 
     }
 
     @Override
     public void addLast(E element) {
+        DLNode<E> temp = new DLNode<E>(element);
+        temp.setPrev(trailer.getPrev());
+        temp.getPrev().setNext(temp);
+        temp.setNext(trailer);
+        trailer.setPrev(temp);
+        nelements++;
 
     }
 
     @Override
     public E removeFirst() throws EmptyDequeException {
-        return null;
+        if (isEmpty()){
+            throw new EmptyDequeException();
+        } else {
+            DLNode<E> temp = header.getNext();
+            header.setNext( header.getNext().getNext());
+            header.getNext().setPrev(header);
+            nelements--;
+            return temp.getElement();
+        }
     }
 
     @Override
     public E removeLast() throws EmptyDequeException {
-        return null;
+        if (isEmpty()){
+            throw new EmptyDequeException();
+        } else {
+            DLNode<E> temp = trailer.getPrev();
+            trailer.setPrev(trailer.getPrev().getPrev());
+            trailer.getPrev().setNext(trailer);
+            nelements--;
+            return temp.getElement();
+        }
     }
+
+
+    @Override
+    public String toString() {
+
+        String to_return = "";
+        to_return = to_return + "[";
+
+        for (  DLNode<E> temp = header.getNext(); temp != trailer ; temp = temp.getNext()){
+
+            if ( temp.getNext() == trailer){
+                to_return+=(temp.getElement().toString());
+            }else{
+                to_return+=( temp.getElement().toString() + ",");
+            }
+        }
+        to_return = to_return + "]";
+
+        return to_return;
+    }
+
+    private DLNode<E> header = new DLNode<E>();
+    private DLNode<E> trailer = new DLNode<E>();
+    private int nelements = 0;
+
 }