iluwatar#90 Added comments for the example code.

front-controller/src/main/java/com/iluwatar/App.java

@@ -1,5 +1,23 @@
 package com.iluwatar;
 
+/**
+ * 
+ * The Front Controller is a presentation tier pattern. Essentially it defines a
+ * controller that handles all requests for a web site.
+ * 
+ * The Front Controller pattern consolidates request handling through a single handler
+ * object (FrontController). This object can carry out the common the behavior such as
+ * authorization, request logging and routing requests to corresponding views.
+ * 
+ * Typically the requests are mapped to command objects (Command) which then display
+ * the correct view (View).
+ * 
+ * In this example we have implemented two views: ArcherView and CatapultView. These
+ * are displayed by sending correct request to the FrontController object. For example,
+ * the ArcherView gets displayed when FrontController receives request "Archer". When
+ * the request is unknown, we display the error view (ErrorView).
+ *
+ */
 public class App {
 
 	public static void main(String[] args) {

front-controller/src/main/java/com/iluwatar/ArcherCommand.java

@@ -1,5 +1,10 @@
 package com.iluwatar;
 
+/**
+ * 
+ * Command for archers.
+ *
+ */
 public class ArcherCommand implements Command {
 
 	@Override

front-controller/src/main/java/com/iluwatar/ArcherView.java

@@ -1,5 +1,10 @@
 package com.iluwatar;
 
+/**
+ * 
+ * View for archers.
+ *
+ */
 public class ArcherView implements View {
 
 	@Override

front-controller/src/main/java/com/iluwatar/CatapultCommand.java

@@ -1,5 +1,10 @@
 package com.iluwatar;
 
+/**
+ * 
+ * Command for catapults.
+ *
+ */
 public class CatapultCommand implements Command {
 
 	@Override

front-controller/src/main/java/com/iluwatar/CatapultView.java

@@ -1,5 +1,10 @@
 package com.iluwatar;
 
+/**
+ * 
+ * View for catapults.
+ *
+ */
 public class CatapultView implements View {
 
 	@Override

front-controller/src/main/java/com/iluwatar/Command.java

@@ -1,5 +1,10 @@
 package com.iluwatar;
 
+/**
+ * 
+ * Commands are the intermediary between requests and views.
+ *
+ */
 public interface Command {
 
 	void process();

front-controller/src/main/java/com/iluwatar/ErrorView.java

@@ -0,0 +1,14 @@
+package com.iluwatar;
+
+/**
+ * 
+ * View for errors.
+ *
+ */
+public class ErrorView implements View {
+
+	@Override
+	public void display() {
+		System.out.println("Error 500");
+	}
+}

front-controller/src/main/java/com/iluwatar/FrontController.java

@@ -1,5 +1,11 @@
 package com.iluwatar;
 
+/**
+ * 
+ * FrontController is the handler class that takes in all the requests and
+ * renders the correct response.
+ *
+ */
 public class FrontController {
 
 	public void handleRequest(String request) {

front-controller/src/main/java/com/iluwatar/UnknownCommand.java

@@ -1,9 +1,14 @@
 package com.iluwatar;
 
+/**
+ * 
+ * Default command in case the mapping is not successful.
+ *
+ */
 public class UnknownCommand implements Command {
 
 	@Override
 	public void process() {
-		System.out.println("Error 500");
+		new ErrorView().display();
 	}
 }

front-controller/src/main/java/com/iluwatar/View.java

@@ -1,5 +1,10 @@
 package com.iluwatar;
 
+/**
+ * 
+ * Views are the representations rendered for the user.
+ *
+ */
 public interface View {
 
 	void display();