Why Angular?

• Angular is a Component-Based Framework.  A component has a view, logic, and data as one unit.  The view is responsible for the display of the component.  The model is defined in the component class.  The component class interacts with view to display data and reacts to user interactions.  The component class also interacts with services to retrieve data and save user inputs.
• Angular uses Services for data or logic that is not associated with a specific view. Services fetch data from the server.  Service class keep your component classes lean and efficient.
• Typescript classes, and Dependency injection feature make your code easy to maintain
• Angular is easy to learn for Java Developers

Why Spring Restful?

• Spring is the de facto standard to build Java web application.
• Spring application is easy to maintain

Why CAS Authentication?

• Cas is a widely used Single sign-on, open source Java project.
• Applications don’t need to maintain authentication information

Sequence Diagram

• User clicks on the Sign-on button on the angular application
• Angular redirects the user to Single sign-on page
• User signs in
• CAS server redirects the user to a restful URL
• Spring restful service calls CAS server to validate user’s authentication
• Spring restful service creates a user session
• Angular will be able to call Spring protected services now