Backing bean:
A typical JavaServer Faces application includes one or more backing beans, each of which is a type of JavaServer Faces managed bean that can be associated with the components used in a particular page. This section introduces the basic concepts of creating, configuring, and using backing beans in an application.
templates/seatBooking.html:
<!DOCTYPE html> <html lang="en" xmlns:th="http://www.thymeleaf.org"> <head> <meta charset="UTF-8"> <title>Theater Booking</title> </head> <body> <h1>Theater Booking</h1> <h2>Seat availability</h2> <form action="/checkAvailability" th:object="${bean}" method="POST"> <p>Check if seat number <select th:field="*{selectedSeatNum}"> <option th:each="n : ${bean.seatNums}" th:value="${n}" th:text="${n}" /> </select> in row <select th:field="*{selectedSeatRow}"> <option th:each="r : ${bean.seatRows}" th:value="${r}" th:text="${r}" /> </select> is available <input type="submit"/></p> </form> <p th:text="${bean.result}"></p> </body> </html>
Create bean and connect to controller:
package com.virtualpairprogrammers.theater.control import org.springframework.stereotype.Controller import org.springframework.web.bind.annotation.RequestMapping import org.springframework.web.servlet.ModelAndView @Controller class MainController { @RequestMapping("") fun homePage() : ModelAndView { return ModelAndView("seatBooking", "bean", CheckAvailabilityBackingBean()) } } class CheckAvailabilityBackingBean() { val seatNums = 1..36 val seatRows = 'A'..'O' var selectedSeatNum: Int = 1 var selectedSeatRow: Char = 'A' var result: String = "" }