Java Interview Questions


  1. What is difference between Hashtable and HashMap classes in Java?
  2. What is CuncurrentMap?
  3. What is Fail fast iterator and fail safe iterator?
  4. How Fail fast iterator knows that the internal structure of collection is modified?
  5. What is priority query?
  6. What is annotations? how to create custom annotation and use it?
  7. What is dependency injection?
  8. What is use of Junit?
  9. What is AOP? Explain its terminology?
  10. What is design pattern & why should we use them?
  11. Explain different type of design patterns.
  12. What is file in Java?
  13. What is difference between OOP and AOP?
  14. What is difference between  application server and web server?
  15. What is difference between SOAP and RESTful web services?
  16. What are implicit objects of JSP?
  17. How to integrate Hibernate with Spring?
  18. What is difference between logical and physical transaction?
  19. Explain Memory management in Java.
  20. Explain memory management of String in java.
  21. What is wait() and notify() methods?
  22. Explain JVM architecture?
  23. What is String constant poll?
  24. What is Class in java ?
  25. What is volatile keyword? 
  26. What is Lock interface?
  27. Sort a list with single loop.
  28. Find a missing number in list using single loop.
  29. Find common elements from two list without using for loop.
  30. what is difference between JVN, JRE, JDK?
  31. what is difference between Comparator and Comparable in Java?
  32. What is difference between String and StringBuffer
  33. What is Service Oriented Architecture(SOA)

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