Although creating a POJO can be an efficient way of creating simple classes, it can be limiting to have a concrete class definition scattered through the class definitions. It is a better design to use either an abstract class or an interface as the service type.
Create a new interface in the
com.packtpub.e4.applicationpackage, calledIStringService. Define theprocessmethod as abstract:public interface IStringService { public abstract String process(String string); }Modify the existing
StringServiceso that it implements theIStringServiceinterface:public class StringService implements IStringService { ... }Modify the reference in the
Rainbowclass to refer to theIStringServiceinterface instead of theStringServiceclass:@Inject private IStringService stringService;
Run the application, switch to the Rainbow tab, and a dependency injection fault will be shown in the host Eclipse instance's Console view:
org.eclipse.e4.core.di.InjectionException...