Wipro Sr. Software Engineer interview questions

1. When to use Runnable and when to use Thread 2. Some important methods of Thread(sleep,wait) 3. Future object 4. Callable 5. What type of value Thread returns.or any method inside thread returns. 6. Swap two variables without using 3rd variable; 7. Find occurence of elements using stream api. 8. Find duplicate elem using stream api 9. Factory vs abstract factory design pattern 10.Difference Between BeanFactory and ApplicationContext 11.How to make mutable class 1. Final method, variables, classs 2. How to make Singleton class 3. String literal and string object with new keyword. How does it differ behind 4. Java 8 features 5. Added date and time features in java 8 6. @component and @Componentscan 7. Stereotypes annotations 8. What type of initialisation is streams(lazy or eager) - ans:- lady because it has intermediate operation first nd then only terminate operation 9. Optional class 10. Throw and throws 11. Checked Exception(compiler) and unchecked exception(runtime)

SOLID Principles, RestFul, POST vs PUT, Statelessness in Rest, caching mechanisms, Spring Cloud