Design Pattern - Front Controller Pattern


The front controller design pattern is used to provide a centralized request handling mechanism so that all requests will be handled by a single handler. This handler can do the authentication/ authorization/ logging or tracking of request and then pass the requests to corresponding handlers. Following are the entities of this type of design pattern.

  • Front Controller - Single handler for all kinds of requests coming to the application (either web based/ desktop based).

  • Dispatcher - Front Controller may use a dispatcher object which can dispatch the request to corresponding specific handler.

  • View - Views are the object for which the requests are made.


We are going to create a FrontController and Dispatcher to act as Front Controller and Dispatcher correspondingly. HomeView and StudentView represent various views for which requests can come to front controller.

FrontControllerPatternDemo, our demo class, will use FrontController to demonstrate Front Controller Design Pattern.

Front Controller Pattern UML Diagram

Step 1

Create Views.

public class HomeView {
   public void show(){
      System.out.println("Displaying Home Page");

public class StudentView {
   public void show(){
      System.out.println("Displaying Student Page");

Step 2

Create Dispatcher.

public class Dispatcher {
   private StudentView studentView;
   private HomeView homeView;
   public Dispatcher(){
      studentView = new StudentView();
      homeView = new HomeView();

   public void dispatch(String request){

Step 3

Create FrontController

public class FrontController {
   private Dispatcher dispatcher;

   public FrontController(){
      dispatcher = new Dispatcher();

   private boolean isAuthenticUser(){
      System.out.println("User is authenticated successfully.");
      return true;

   private void trackRequest(String request){
      System.out.println("Page requested: " + request);

   public void dispatchRequest(String request){
      //log each request
      //authenticate the user

Step 4

Use the FrontController to demonstrate Front Controller Design Pattern.

public class FrontControllerPatternDemo {
   public static void main(String[] args) {
      FrontController frontController = new FrontController();

Step 5

Verify the output.

Page requested: HOME
User is authenticated successfully.
Displaying Home Page
Page requested: STUDENT
User is authenticated successfully.
Displaying Student Page