Synechron interview question

Q1) Write simple java code for ,whether given string have character "i" ,using stream API only. Ex: If input is "hello" word, output will be false, as the word doesn't have letter "i". Q2) what is volatile keyword is used for? Q3)explain oops concepts? Q4)why java doesn't support multiple inheritance, what happens if we try to implement? can you explain with some example ? Q5)what is multi threading? Do you know about executor ? Q6)what is REST? Q7)When we are opening a google page, which type of request it is?GET or POST or other requests? Q8)how Requests are mapping with servlets in SPRING MVC? can you explain? Q9)Why spring boot s required,when we have many spring components already?Advanatages of Springboot? Q10)what is Springboot profiling concept? Q11)What are the things you write or configure,in your spring boot application,related to tomcat? Q12)what collections you used in your project?explain How hashmap buckets internally works? Q13)DIfference between HTTP and HTTPS? Q14)What type of errorcodes you get genearlly, when you access a REST webservice using browser? etc