adding final version ocp

Author: ccarella

README.md

@@ -1,3 +1,27 @@
-Design Principles
+### Design Principles
 
-Solid Java
+## Solid Java
+
+Design principles encourage us to create more maintainable, understandable, and flexible software. Consequently, 
+as our applications grow in size, we can reduce their complexity
+
+### Single Responsability
+
+**A class should only have one responsibility. Furthermore, it should only have one reason to change.**
+
+In `BookV1` the print method violates the SRP. For this reason the `BookV2` is amended to remove the method and 
+`BookPrinter` is implemented a separate class that is concerned only with printing.
+
+Not only have we developed a class that relieves the Book of its printing duties, but we can also leverage our 
+`BookPrinter` class to send our text to other media.
+
+### Open for Extension, Closed for Modification
+
+**Classes should be open for extension, but closed for modification.**
+
+After the first implementation of `Guitar`, we want to add in a second implementation, a flame pattern.
+It might be tempting to just open up the `Guitar` class and add a flame pattern – but who knows what errors that might 
+throw up in our application.
+
+Following OCP we create `SuperCoolGuitarWithFlames` by extending the Guitar class we can be sure that our existing 
+application won't be affected.

src/main/java/ocp/Guitar.java

@@ -16,23 +16,12 @@ public String getMake() {
         return make;
     }
 
-    public void setMake(String make) {
-        this.make = make;
-    }
-
     public String getModel() {
         return model;
     }
 
-    public void setModel(String model) {
-        this.model = model;
-    }
-
     public int getVolume() {
         return volume;
     }
 
-    public void setVolume(int volume) {
-        this.volume = volume;
-    }
 }

src/main/java/ocp/SuperCoolGuitarWithFlames.java

@@ -0,0 +1,14 @@
+package ocp;
+
+public class SuperCoolGuitarWithFlames extends Guitar {
+
+    private String flameColor;
+
+    public SuperCoolGuitarWithFlames(String make, String model, int volume) {
+        super(make, model, volume);
+    }
+
+    public String getFlameColor() {
+        return flameColor;
+    }
+}