Building Java Web Applications with Spring Web MVC - Learn Java for Web Development - page 210

Listing 5-13. Vehicle Service
1. public class VehicleService {
2.
3. private Vehicle vehicle = new Bike();
4.
5. public void driver() {
6. System.out.println(vehicle.drive());
7.
8. }
9.
10. }
 Line 3 : In Listing 5-13, class Bike is the dependency of class VehicleService
and is instantiated on line 3. This is a case of tight coupling because the class
VehicleService is implementation-aware of the Vehicle object, which is Bike in
this case.
Listing 5-14 illustrates the stand-alone VehicleApp .
Listing 5-14. Stand-Alone VehicleApp
1. public class VehicleApp {
2. public static void main(String[] args) {
3. VehicleService service = new VehicleService();
4. service.driver();
5. }
6. }
As illustrated in Listing 5-14, VehicleService is implementation-aware of the Vehicle object and
hence tightly coupled to it. Now let's decouple this application through the Spring Framework's DI.
The first step is to create a Java project using the Eclipse IDE. Select File ➤ New ➤ Project and
then select Java Project Wizard from the wizard list. Name your project looselyCoupledApplication
using the wizard, as illustrated in Figure 5-2 .