Code for the create action Code added to the controller @GetMapping("/create") public String create(Model model) { model.addAttribute("student", new Student()); return "create"; } @PostMapping("/create") public String create(@ModelAttribute Student stu) { String index = Integer.toString(students.size() + 1); stu.setStudentId(index); students.add(stu); return "redirect:/"; } create.html <form method="Post" th:action="@{/create}" th:object="${student}"> <input type="text" th:field="*{firstName}" /> <input type="text" th:field="*{lastName}"/> <input type="date" th:field="*{enrollmentDate}"/> <input type="text" th:field="*{cpr}"/> <input type="submit" value="Send" /> </form> Student.java //needed for input field on html pages (in order to serve the right format) @DateTimeFormat(pattern = "yyyy-MM-dd") private Date enrollmentDate;