Feature 4

Feature 4 is retrieving the book categories from the database and display it in the webpage. In feature 3 we have hard-coded the book categories in the view template. In feature 4 we make a HTTP GET call to the rest end point and the spring backend application will talk to the database and returns the JSON response back to the angular application. Then, in our angular application we call the service method and get the book categories. Finally, in our view template we will loop through the categories and display it in the webpage.