Top Java Design Pattern Interview Questions for Experienced – Must prepare

Here is the list of best java design pattern interview questions for experienced and freshers asked in real time interviews.


1. When to use Strategy Design Pattern in Java?
2. What is Observer design pattern in Java? When do you use Observer pattern in Java?
3. Difference between Strategy and State design Pattern in Java?
4. What is decorator pattern in Java? Can you give an example of Decorator pattern?
5. When to use Composite design Pattern in Java? Have you used previously in your project?
6. What is Singleton pattern in Java? 
7. Can you write thread-safe Singleton in Java?
8. When to use Template method design Pattern in Java?
9. What is Factory pattern in Java? What is advantage of using static factory method to create object?
10. Difference between Decorator and Proxy pattern in Java?
11. What is Builder design pattern in Java? When do you use Builder pattern ?
12. Can you give an example of  SOLID design principles in Java?
13. When to use Setter and Constructor Injection in Dependency Injection pattern?
14. What is difference between Factory and Abstract factory in Java
15. When to use Adapter pattern in Java? Have you used it before in your project?