Persistent Systems interview question

01. Collection? 02. What Collections do you know? 03. What is HashMap? 04. HashMap implementation? 05. What is Synchronization? 06. Tell me how synchronization works? 07. Scenario based question on declaring a candidate as winner in an election? Used List and Comparator to solve it? 08. How you maintain Spring application in multiple environment lik QA, Dev/producton etc 09. Bean Scopes? 10. Difference between Singleton and Prototype Scope? 11. What is DI? 12. What is the responsibility of IOC Container in Spring? 13. What is DispatcherServlet? 14. Inject Address into an Employee class? 15. How do you inject one service to another service? 16. How will you validate empName property which is passed in the body of the request in Employee object? 17. Can you explain how the request coming to your defined function addEmployee() in the above code snippet? 18. What is Router in Angular? 19. What is Form validation? 20. Async validation in Form? Validate whether the entered User name is available or not? 21. How do you write test cases in Angular?