Six Dee Telecom Solutions interview question

1. Basic core java questions 2. questions o n collections like difference between HashMap and ConcurrentHashMap,internal implementation of HashMap 3.Which collection is used to maintain unique elements 4.When ins ArrayList and LinkedList used 5.Programming questions on threads,synchronization,wait,notify 6. few basic programming questions like find the second highest element of an array without sorting etc 7.Basic linux commands 8. JVM memory structure, what is stack heap etc