Java/j2ee interview questions
1. What is connection pooling?
2. What is externalization and serialization?
ANS- It is the process of storing the object state into persistent state. Whereas in the case of externalization jvm will take care.
3. What is jar,war and ear
4. How is validation done validator.xml in struts?
5. How do you set connection pooling?
6. What is the use of web service?
7. What is the use of static?
8. Which collection is the best?
9. What is difference between set and list?
10. How to calculate the efforts for screen enhancement?
11. How to retain session values?
12. You are redirecting your web page to another page for password validation when come back to previous page, what will be the session value i.e same session value or different value
13. When the session is created which event is called?
14. What is difference between HashTable and HashMap?
15. How to set the session time out value?
16. How to improve the performance of the project?
17. What is use of finalize() method?
18. Why you go for HashTable?
19. Overriding and overloading?
20. How to convert list duplicate values to non-duplicatable?
21. What is AJAX?
22. What is XSD?
23. What is thread?
24. Which java coding standard is useful one.
25. What is static?
26. What is the different kind of Exception?
27. What is final and finally?
28. What are the xml Parser?
29. How to declare the array structure like below?
30.how to declare HashMap such away it accept only Boolean value?
31.How to make arraylist as synchronized one?
32.Differnce between Apache and Tomcat?
33.How to set connection pooling in Tomcat?
34.what is statement and explain callable and prepared statement?
35.how to configure jsp page in web.xml?
36.what is difference of creating RequestDispatcher by using getRequest Dispatcher and ServletContext?
37.what is the advantage of using Appserver?
38.How to swap the variable without using temp?
39.what is the difference between CGI and Servlet ?
40.How to prevent the Instance from outside class not in the same class?
41.String s1 = new String (“abc”)
S1.replace(‘a’,’b’);
42.How to compare Strings?
43.what is the difference between “= =” and equals() method?
44.what is Autoboxing?
45.what is JDK 1.5 features?
46.what is the size of ArrayList?
47. how to represent the class A contains class B in UML Notation?
48.what it business delegation?
49.how to catch the errors from package?
50.why do we go for taglib?
51.what is difference between session and hidden variables?
52.How jsp is going to be converted into servlet?
53.How to navigate in Struts?
54.How to display a set of values from db to JSP?
55.what is trigger?
56.How to check particular string contains in a List?
57.what is the difference between Application Scope and session Scope?
58.why do we go for taglib?
59.what is difference between session and hidden variable?
60.How to estimate as interms of function Points (FP)?
61.what are the documents in functional specification?
62.what are the difference JSP Tags?
63.what is init method in Servlet?
