The code in frontend folder was made only for the ease of testing the backend and would be written completely in a different way if assignment required a UI -> as an example click https://github.com/mtroskot/Diplomarbeit-Dreambnb/tree/master/frontend.
To run the backend, import it in eclipse and run it. When dev profile is active, test data is loaded in H2 database. The H2 console can be accessed at http://localhost:8084/h2-console/ . To test the backend, download the frontend, in frontend folder run: npm install to get node modules, after the node modules are downloaded run : npm start. The frontend displays information about Number of discounts, TotalBillDiscountPercentage, TotalPriceWithDiscountsn, TotalPriceWithoutDiscounts, Products in basket. More information, price of each product in basket,discounts etc. can be seen in the developers console.