Interviewer was friendly.

Some/all of the questions he asked:

• diff between int and Integer
• diff between == and equals()
• what do you need to do when you override equals() and why?
• diff between abstract and interface
• what is enum class
• have you used JMX at all?
• what is a thread? how do you create a thread in java?
• what is thread and Runnable?
• do the threads start automatically when you create them?
• what are the problems with multithreading? how to avoid them?
• what is synchronization?
• when you create a method with synchronize, is the method synchronized, or the variables?
• if one thread is running the method, can other threads run other methods in the class?
• what is the downside of synchronization?
• what is serialization? how do you achieve this in java?
• what is the difference between the class that extends Exception and RuntimeException?
• what are checked/unchecked exceptions?
• Have you done any UnitTesting? have you used JUnit/TestNG?
• difference between ArrayList and Vector?
• What is aspect programming?
• what is dependency injection?
• Do you have experience with Ant/Maven?
• What is a final variable, method, or class?
• What are the different parsing methods available to parse XML?
• diff between DOM and SAX?
• diff between http GET and POST?
• diff between TCP and UDP?
• what command do you use to check the running servers in a UNIX/LINUX environment?

What is enum class?