Yogesh's Tech Blog

NPE as well as Null check free code … Really ? Is this how your Java code review start ? NPE is always nightmare for a Java developer. Lets not discussion to much and jump on an usual Java code snippet public interface Service { public boolean switchOn(int timmer); public boolean switchOff(int timmer); //Other controls } public class RefrigeratorService implements Service { // ... } public class HomeServices { private static final int NOW = 0; private static HomeServices service; public static HomeServices get() { //Null Check #1 if(service == null) { service = new HomeServices(); } return service; } public Service getRefrigertorControl() { return new RefrigeratorService(); } public static void main(String[] args) { /* Get Home Services handle */ HomeServices homeServices = HomeServices.get(); //Null Check #2 if(homeServices != null) { Serv...

Java doesn’t have “Diamond” problem : Really ..? We have been confidently telling that Java doesn’t have diamond problem even if it support multiple inheritance. In object-oriented programming languages with multiple inheritance and knowledge organization, the diamond problem is an ambiguity that arises when two classes B and C inherit from A, and class D inherits from both B and C. But do you that the diamond problem is now there in newly introduced Java 8. It is because of the introduction of default methods in Interface. In Java8 Interfaces not only have method declaration but their default implementation. Any class implementing can either use default implementation from interface or provide its own implementation. Since Java class can implement multiple interfaces it is possible that two interfaces has same default methods, that brings diamond problem. How do we overcome diamond problem ? Consider following code snippet public interface InterfaceA { ...