
- Design Patterns Tutorial
- Design Patterns - Home
- Design Patterns - Overview
- Design Patterns - Factory Pattern
- Abstract Factory Pattern
- Design Patterns - Singleton Pattern
- Design Patterns - Builder Pattern
- Design Patterns - Prototype Pattern
- Design Patterns - Adapter Pattern
- Design Patterns - Bridge Pattern
- Design Patterns - Filter Pattern
- Design Patterns - Composite Pattern
- Design Patterns - Decorator Pattern
- Design Patterns - Facade Pattern
- Design Patterns - Flyweight Pattern
- Design Patterns - Proxy Pattern
- Chain of Responsibility Pattern
- Design Patterns - Command Pattern
- Design Patterns - Interpreter Pattern
- Design Patterns - Iterator Pattern
- Design Patterns - Mediator Pattern
- Design Patterns - Memento Pattern
- Design Patterns - Observer Pattern
- Design Patterns - State Pattern
- Design Patterns - Null Object Pattern
- Design Patterns - Strategy Pattern
- Design Patterns - Template Pattern
- Design Patterns - Visitor Pattern
- Design Patterns - MVC Pattern
- Business Delegate Pattern
- Composite Entity Pattern
- Data Access Object Pattern
- Front Controller Pattern
- Intercepting Filter Pattern
- Service Locator Pattern
- Transfer Object Pattern
- Design Patterns Resources
- Design Patterns - Questions/Answers
- Design Patterns - Quick Guide
- Design Patterns - Useful Resources
- Design Patterns - Discussion
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
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.
Implementation
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.

Step 1
Create Views.
HomeView.java
public class HomeView { public void show(){ System.out.println("Displaying Home Page"); } }
StudentView.java
public class StudentView { public void show(){ System.out.println("Displaying Student Page"); } }
Step 2
Create Dispatcher.
Dispatcher.java
public class Dispatcher { private StudentView studentView; private HomeView homeView; public Dispatcher(){ studentView = new StudentView(); homeView = new HomeView(); } public void dispatch(String request){ if(request.equalsIgnoreCase("STUDENT")){ studentView.show(); } else{ homeView.show(); } } }
Step 3
Create FrontController
FrontController.java
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 trackRequest(request); //authenticate the user if(isAuthenticUser()){ dispatcher.dispatch(request); } } }
Step 4
Use the FrontController to demonstrate Front Controller Design Pattern.
FrontControllerPatternDemo.java
public class FrontControllerPatternDemo { public static void main(String[] args) { FrontController frontController = new FrontController(); frontController.dispatchRequest("HOME"); frontController.dispatchRequest("STUDENT"); } }
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