import java.util.List;
            // Controller
            public class NewsController {
                // Internal reference to the service used by this client
                private NewsServices newsServices;

                public NewsController(NewsServices newsServices){
                    // Constructor injection
                    this.newsServices = newsServices;
                }
                // Injected Methods
                public List getAll() {
                    return newsServices.findAll();
                }
                public News getOne(int id){
                    return newsServices.findOne(id);
                }

            }

// Entity
        public class News {
            private int id;
            private String title;
            private String description;
            private boolean deleted;
        
            public News(String title,String description){
                this.title = title;
                this.description = description;
            }
        
            // getter setter etc
            
        }

Dependency injection is basically providing the objects that an object needs 
(its dependencies) instead of having it construct them itself. 

It's a very useful technique for testing, since it allows dependencies 
to be mocked or stubbed out.

Class A   Class B   if A uses some methods of B then its a dependency injection