difference between comparator and compare difference between string and string buffer what is stratagy pattern how will use spring with hibernate what is singleton pattern when a singleton pattern fails incase of threads difference between hash map and hash table how to declare java generics how 2 threads can access a variable (how to establish the communication between 2 threads) what is ENUM roll in threads What design pattens you have used what is java cloning what will happen to singleton object incase of clone what yeid method what version of EJB you have used what is globle and local transcations what is spring autowiring which type of autowiring is good (constructor or setter) what happens if you autowire interface which is implemented by 2 classes