Spring MVC Fast Tutorial: Model View Controller
What are we going to build?
A page displaying a car list.
We need:
- Model classes: Car and Brand
- Manager class: to obtain a list of Cars
- Controller class: will use the list method from the Manager
- View (JSP): display the car list
Model classes
'WEB-INF/src/springmvc/model/Brand.java'
package springmvc.model; public class Brand { private Long id; private String name; private String country; public String getCountry() { return country; } public void setCountry(String country) { this.country = country; } public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } }
'WEB-INF/src/springmvc/model/Car.java'
package springmvc.model; import java.math.BigDecimal; public class Car { private Long id; private Brand brand; private String model; private BigDecimal price; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public Brand getBrand() { return brand; } public void setBrand(Brand brand) { this.brand = brand; } public String getModel() { return model; } public void setModel(String model) { this.model = model; } public BigDecimal getPrice() { return price; } public void setPrice(BigDecimal price) { this.price = price; } }
Manager Class
To keep things simple, we use a static list instead of a database.
'WEB-INF/src/springmvc/service/CarManager.java'
package springmvc.service; import java.math.BigDecimal; import java.util.LinkedList; import java.util.List; import springmvc.model.Brand; import springmvc.model.Car; public class CarManager { private static List<Car> carList; static { Brand brand1 = new Brand(); brand1.setId((long)1); brand1.setName("Mercedes"); brand1.setCountry("Germany"); Brand brand2 = new Brand(); brand2.setId((long)2); brand2.setName("Peugeot"); brand2.setCountry("France"); Car car1 = new Car(); car1.setId((long)1); car1.setBrand(brand1); car1.setModel("SL 500"); car1.setPrice(new BigDecimal(40000)); Car car2 = new Car(); car2.setId((long)2); car2.setBrand(brand2); car2.setModel("607"); car2.setPrice(new BigDecimal(35000)); carList = new LinkedList<Car>(); carList.add(car1); carList.add(car2); } public List<Car> getCarList() { return carList; } }
Controller
In 'WEB-INF/springmvc-servlet.xml', we declare a new URL:
<bean name="/list_cars.html" class="springmvc.web.CarListController"/>
We now create this Controller: 'WEB-INF/src/springmvc/web/CarListController.java'
package springmvc.web; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.Controller; import springmvc.service.CarManager; public class CarListController implements Controller { public ModelAndView handleRequest(HttpServletRequest arg0, HttpServletResponse arg1) throws Exception { CarManager carManager = new CarManager(); ModelAndView modelAndView = new ModelAndView("carList"); modelAndView.addObject("carList", carManager.getCarList()); return modelAndView; } }
View
The view 'carList' declared above: 'jsp/carList.jsp':
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <html> <body> <h1>Car List</h1> <c:forEach items="${carList}" var="car"> ${car.brand.name} ${car.model}: ${car.price} <br /> </c:forEach> </body> </html>
Result
Build (ant), relaunch Tomcat and check it's working: http://localhost:8180/springmvc/list_cars.html
Summary
Your project now looks like that:
You can download it here.
We just built a complete Spring MVC application:
- model classes
- service/manager class
- controller class
- view (JSP)
Previous: Hello World --- Up: Spring Fast Tutorial --- Next: Form Processing