Pergunta de entrevista da empresa Iris Software

Q1. What is java memory model explain it? Q2. How Hashmap works internally many questions on the hashmap working. a. What is the data structure is used to store entity? b. how hashcode works with the performace of hashmap? c. What is the good way to override hashmap? d. Which version of java uses Red Black tree for storing hash entity having hashcode collision? e. What is hash collision explain that. write some code which uses a class as key and override hashcode and equals mehod in that. f.write code for good hashcode. Q3 What is Executor framework in java? a. write code for creating threads using executor framework. b. How will you assign threads doing subtask in executor framework? c. What is Lock? d. which is concurrency package, what are the classes in that? e. what is semaphore? Where it is used? f.Tell something about producer and consumer problem, which class of queue interface is used to solve it? Q4 How ArrayList works? which Collection is resizable? when arraylist grows what is the new size?