The best Front Controller pattern Tutorial In 2024, In this tutorial you can learn achieve,step 1,Step 2,Step 3,Step 4,Step 5,

Front Controller pattern

Front Controller pattern (Front Controller Pattern) is used to provide a centralized mechanism for handling requests, all requests are processed by a single handler. The handler can do authentication / authorization / logging or tracking request, then the request to the appropriate handler. The following is an entity of this design pattern.

• Front Controller (Front Controller) - a single handler to process all types of requests an application, the application may be a web-based application that can be desktop-based applications.
• Scheduler (Dispatcher) - front-end controller may use a dispatcher object to dispatch the request to the appropriate specific handler.
• View (View) - view is the object of the request and created.

achieve

We will createFrontController,Dispatcher, respectively, as the front-end controller and scheduler.HomeViewandStudentViewview showing a variety of front-end controller receives a request to create.

FrontControllerPatternDemo,our demonstration class to demonstrate the useFrontControllerFront Controller design pattern.

step 1

Create the view.

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.

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

Creating a front controller FrontController.

Context.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) {
      // Record every request trackRequest (request);
      // To authenticate the user if (isAuthenticUser ()) {
         dispatcher.dispatch (request);
      }	
   }
}

Step 4

FrontControllerto demonstrate the use of the 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 output.

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