Tata Consultancy Services Java Production Support interview questions

*DateTime API and why *FunctionalInterface why *Default method why *How string works internally *Immutable call *Call by value vs call by reference *Internal working of HashMap *@Component scanning use @RestController @PostMapping post vs put - what happens if we use put for creating an object @headrequest @option @configuration @how you use prefix and suffix in @configuration use of JPA normal forms explanation