JAVA EXAMPLE PROGRAMS

JAVA EXAMPLE PROGRAMS

Publish Your Article Here

What is interface default method in java 8?


Answer:

Before Java 8, the interface only contains method signatures. With Java 8 new feature Default Methods or Defender Methods, you can include method body within the interface.

All you need to do is add "default" keyword infront of the implementation method with in the interface. This is the new way of declaring the method body in Java 8 for an interface, default methods comes along with implementation.

Why do we need to implement a method within the interface?

Let's say you have an interface which has multiple methods, and multiple classes are implementing this interface. One of the method implementation can be common across the class, we can make that method as a default method, so that the implementation is common for all classes.

How to work with existing interfaces?

Second scenario where you have already existing application, for a new requirements we have to add a method to the existing interface. If we add new method then we need to implement it through out the implementation classes. By using the Java 8 default method we can add a default implementation of that method which resolves the problem.

When working with multiple inheritance:

If we have two interfaces, one with default method and another with just method signature (normal way of defining method in the interfaces).

Refer Java 8 Interface Default Methods for more details.

<< Previous Question | Next Question >>

List Of Java Interview Questions:

  1. Previous set of java interview questions
  2. What is difference between Lambda Expression and Anonymous class?
  3. What is HTTP basic authentication?
  4. What is functional interface in java?
  5. What is the difference between HTTP methods GET and POST?
  6. What is difference between CountDownLatch and CyclicBarrier in Java?
  7. Can Enum extend any class in Java?
  8. Can Enum implements any interface in Java?
  9. Can we have constructor in abstract class?
  10. What is MVC pattern?
  11. What is ActionServlet in struts?
  12. What is the difference between servlet & Filter?
  13. What is ActionMapping in struts?
  14. What is the difference between application server and web server?
  15. What is the difference between JPA and Hibernate?
  16. What is difference between the Value Object and JDO?
  17. How Struts control data flow?
  18. What is Spring?
  19. What is Dependency Injection?
  20. What are the different types of dependency injections in spring?
  21. What is BeanFactory in Spring?
  22. What is difference between BeanFactory and ApplicationContext in spring?
  23. How to make a bean as singleton in spring?
  24. What is IOC or inversion of control?
  25. What are different types of spring auto-wiring modes?
  26. What are the limitations and disadvantages of spring autowiring?
  27. Is the spring singleton bean thread safe?
  28. Why ConcurrentHashMap is faster than Hashtable in Java?
  29. What is the difference between ConcurrentHashMap and Hashtable in Java?
  30. Difference between ConcurrentHashMap and Collections.synchronizedMap(Map)?
  31. What is the difference between ORM, JPA and Hibernate?
  32. What is stream pipelining in Java 8?
  33. What is interface default method in java 8?
  34. Java-8: Interface with default methods vs Abstract class.
  35. What is @SpringBootApplication annotation in Spring boot project?
  36. What Embedded Containers Does Spring Boot Support?
  37. What are the advantages and disadvantages of Spring Boot?
  38. What is Spring Boot Actuator?
  39. What is Spring Boot Initializr?
  40. How does Maven resolve version conflicts of dependencies?
  41. How to reload Spring Boot Application without restarting server?
  42. What is the difference between Spring Boot and the Spring framework?
  43. What are the key components of Spring Boot framework?
  44. What are the different types of bean scope in Spring framework?
  45. What are the standard Spring build-in events?
  46. What is Spring IoC container?
  47. Differences between BeanFactory and the ApplicationContext in Spring framework.
  48. Difference between constructor injection and setter injection in Spring.
  49. How Java-8 Streams differ from collections
  50. What are the various ways to obtain Streams in Java-8?
  51. List Java-8 Streams intermediate operations.
  52. List Java-8 Streams terminal operations.
  53. Can we reuse Java-8 Streams?
  54. Difference between map and flatMap methods in Java 8
  55. What is the difference between Closure and Lambda in Java 8?
  56. Does Java 8 Lambda supports recursive call?
  57. Can Java 8 default methods override equals, hashCode and toString?
  58. Hibernate Eager vs Lazy Fetch Type
  59. What is POJO?
  60. What is HQL (Hibernate Query Language)?
Java2Novice - YouTube Channel
  1. Python Tutorial for Beginners
Knowledge Centre
Pass by value Vs Pass by reference
Pass by value: Passing a copy of the value, not the original reference.

Pass by reference: Passsing the address of the object, so that you can access the original object.
Famous Quotations
I respect faith, but doubt is what gets you an education.
-- Wilson Mizner

About Author

I'm Nataraja Gootooru, programmer by profession and passionate about technologies. All examples given here are as simple as possible to help beginners. The source code is compiled and tested in my dev environment.

If you come across any mistakes or bugs, please email me to [email protected].

Most Visited Pages

Other Interesting Sites

Reference: Java™ Platform Standard Ed. 7 - API Specification | Java™ Platform Standard Ed. 8 - API Specification | Java is registered trademark of Oracle.
Privacy Policy | Copyright © 2019 by Nataraja Gootooru. All Rights Reserved.