added proxy sample

proxy/src/main/java/com/iluwatar/App.java

@@ -0,0 +1,16 @@
+package com.iluwatar;
+
+public class App 
+{
+    public static void main( String[] args )
+    {
+
+    	WizardTowerProxy tower = new WizardTowerProxy();
+    	tower.enter(new Wizard("Red wizard"));
+    	tower.enter(new Wizard("White wizard"));
+    	tower.enter(new Wizard("Black wizard"));
+    	tower.enter(new Wizard("Green wizard"));
+    	tower.enter(new Wizard("Brown wizard"));
+        
+    }
+}

proxy/src/main/java/com/iluwatar/Wizard.java

@@ -0,0 +1,16 @@
+package com.iluwatar;
+
+public class Wizard {
+
+	private String name;
+
+	public Wizard(String name) {
+		this.name = name;
+	}
+
+	@Override
+	public String toString() {
+		return name;
+	}
+	
+}

proxy/src/main/java/com/iluwatar/WizardTower.java

@@ -0,0 +1,9 @@
+package com.iluwatar;
+
+public class WizardTower {
+
+	public void enter(Wizard wizard) {
+		System.out.println(wizard + " enters the tower.");
+	}
+	
+}

proxy/src/main/java/com/iluwatar/WizardTowerProxy.java

@@ -0,0 +1,19 @@
+package com.iluwatar;
+
+public class WizardTowerProxy extends WizardTower {
+
+	private static final int NUM_WIZARDS_ALLOWED = 3;
+	
+	private int numWizards;
+	
+	@Override
+	public void enter(Wizard wizard) {
+		if (numWizards < NUM_WIZARDS_ALLOWED) {
+			super.enter(wizard);
+			numWizards++;
+		} else {
+			System.out.println(wizard + " is not allowed to enter!");
+		}
+	}
+	
+}