Add Iterator pattern new examples

README.md

@@ -417,5 +417,6 @@ Primero(), Siguiente(), HayMas() y ElementoActual().
 
 **Ejemplos:**
 * [Vectors](https://github.com/peterm85/design-patterns/tree/master/src/iterator/examples/vectors)
+* [Notifications](https://github.com/peterm85/design-patterns/tree/master/src/iterator/examples/notifications)
 
-**Referencia:** [https://www.geeksforgeeks.org/template-method-design-pattern/](https://www.geeksforgeeks.org/template-method-design-pattern/)
+**Referencia:** [https://www.geeksforgeeks.org/iterator-pattern/](https://www.geeksforgeeks.org/iterator-pattern/)

src/iterator/examples/notifications/Client.java

@@ -0,0 +1,9 @@
+package iterator.examples.notifications;
+
+public class Client {
+
+	public static void main(String args[]) { 
+        NotificationBar nb = new NotificationBar(); 
+        nb.printNotifications();
+    }
+}

src/iterator/examples/notifications/Collection.java

@@ -0,0 +1,5 @@
+package iterator.examples.notifications;
+
+public interface Collection {
+	public Iterator createIterator(); 
+}

src/iterator/examples/notifications/Iterator.java

@@ -0,0 +1,7 @@
+package iterator.examples.notifications;
+
+public interface  Iterator {
+	boolean hasNext(); 
+
+    Object next(); 
+}

src/iterator/examples/notifications/Notification.java

@@ -0,0 +1,12 @@
+package iterator.examples.notifications;
+
+public class Notification {
+	String notification; 
+
+    public Notification(String notification) { 
+        this.notification = notification; 
+    } 
+    public String getNotification() { 
+        return notification; 
+    } 
+}

src/iterator/examples/notifications/NotificationBar.java

@@ -0,0 +1,18 @@
+package iterator.examples.notifications;
+
+public class NotificationBar {
+	NotificationCollection notifications; 
+
+    public NotificationBar() { 
+        this.notifications = new NotificationCollection(); 
+    } 
+
+    public void printNotifications() { 
+        Iterator iterator = notifications.createIterator(); 
+        System.out.println("-------NOTIFICATION BAR------------"); 
+        while (iterator.hasNext()) { 
+            Notification n = (Notification)iterator.next(); 
+            System.out.println(n.getNotification()); 
+        } 
+    } 
+}

src/iterator/examples/notifications/NotificationCollection.java

@@ -0,0 +1,32 @@
+package iterator.examples.notifications;
+
+public class NotificationCollection implements Collection { 
+
+	static final int MAX_ITEMS = 6; 
+    int numberOfItems = 0; 
+    Notification[] notificationList; 
+
+    public NotificationCollection() { 
+        notificationList = new Notification[MAX_ITEMS]; 
+
+        // Let us add some dummy notifications 
+        addItem("Notification 1"); 
+        addItem("Notification 2"); 
+        addItem("Notification 3"); 
+    } 
+
+    public void addItem(String str) { 
+        Notification notification = new Notification(str); 
+        if (numberOfItems >= MAX_ITEMS) { 
+            System.err.println("Full"); 
+     	} else { 
+            notificationList[numberOfItems] = notification; 
+            numberOfItems = numberOfItems + 1; 
+        } 
+    } 
+
+    public Iterator createIterator() { 
+        return new NotificationIterator(notificationList); 
+    } 
+
+}

src/iterator/examples/notifications/NotificationIterator.java

@@ -0,0 +1,26 @@
+package iterator.examples.notifications;
+
+public class NotificationIterator implements Iterator { 
+    Notification[] notificationList; 
+
+    int pos = 0; 
+
+    public  NotificationIterator (Notification[] notificationList) { 
+        this.notificationList = notificationList; 
+    } 
+
+    public Object next() { 
+        Notification notification =  notificationList[pos]; 
+        pos += 1; 
+        return notification; 
+    } 
+
+    public boolean hasNext() { 
+        if (pos >= notificationList.length || 
+            notificationList[pos] == null) {
+            return false; 
+        } else {
+            return true;
+        }
+    }
+}