Large Collection of Java Interview Questions

  1. What is the difference between an Abstract class and Interface ?
  2. What is user defined exception ?
  3. What do you know about the garbage collector ?

  4. What is the difference between C++ & Java ?
  5. Explain RMI Architecture?
  6. How do you communicate in between Applets & Servlets ?
  7. What is the use of Servlets ?
  8. What is JDBC? How do you connect to the Database ?
  9. In an HTML form I have a Button which makes us to open another page in 15 seconds. How will do you that ?
  10. What is the difference between Process and Threads ?
  11. What is the difference between RMI & Corba ?
  12. What are the services in RMI ?
  13. How will you initialize an Applet ?
  14. What is the order of method invocation in an Applet ?
  15. When is update method called ?
  16. How will you pass values from HTML page to the Servlet ?
  17. Have you ever used HashTable and Dictionary ?
  18. How will you communicate between two Applets ?
  19. What are statements in JAVA ?
  20. What is JAR file ?
  21. What is JNI ?
  22. What is the base class for all swing components ?
  23. What is JFC ?
  24. What is Difference between AWT and Swing ?
  25. Considering notepad/IE or any other thing as process, What will happen if you start notepad or IE 3 times? Where 3 processes are started or 3 threads are started ?
  26. How does thread synchronization occurs inside a monitor ?
  27. How will you call an Applet using a Java Script function ?
  28. Is there any tag in HTML to upload and download files ?
  29. Why do you Canvas ?
  30. How can you push data from an Applet to Servlet ?
  31. What are 4 drivers available in JDBC ?
  32. How you can know about drivers and database information ?
  33. If you are truncated using JDBC, How can you know ..that how much data is truncated ?
  34. And What situation , each of the 4 drivers used ?
  35. How will you perform transaction using JDBC ?
  36. In RMI, server object first loaded into the memory and then the stub reference is sent to the client ? or whether a stub reference is directly sent to the client ?
  37. Suppose server object is not loaded into the memory, and the client request for it , what will happen?
  38. What is serialization ?
  39. Can you load the server object dynamically? If so, what are the major 3 steps involved in it ?
  40. What is difference RMI registry and OSAgent ?
  41. To a server method, the client wants to send a value 20, with this value exceeds to 20,. a message should be sent to the client ? What will you do for achieving for this ?
  42. What are the benefits of Swing over AWT ?
  43. Where the CardLayout is used ?
  44. What is the Layout for ToolBar ?
  45. What is the difference between Grid and GridbagLayout ?
  46. How will you add panel to a Frame ?
  47. What is the corresponding Layout for Card in Swing ?
  48. What is light weight component ?
  49. Can you run the product development on all operating systems ?
  50. What is the webserver used for running the Servlets ?
  51. What is Servlet API used for connecting database ?
  52. What is bean ? Where it can be used ?
  53. What is difference in between Java Class and Bean ?
  54. Can we send object using Sockets ?
  55. What is the RMI and Socket ?
  56. How to communicate 2 threads each other ?
  57. What are the files generated after using IDL to Java Compilet ?