Java Interview Questions

1. What are the differences between a List and a Set?
2. What are value objects and how are they used with EJBs?
3. How do you code a Singleton in Java?
4. Diffrence between JRE And JVM AND JDK
5. What's a dynamic proxy class?
6. When should you call SwingUtilities.invokeLater()?
7. What are the differences between a Session Bean and an Entity Bean?
8. How do you read an XML file in Java?
9. Give an example of the Decorator pattern in the Java API.
10. Difference between an abstract class and interface
11. Inner classes
12. Difference between an inner class and a normal class
13. What is Entity Bean and Session Bean ?
14. What are the methods of Entity Bean?
15. How does Stateful Session bean store its state ?
16. Why does Stateless Session bean not store its state even though it has ejbActivate and ejbPassivate ?
17. What are the services provided by the container ?
18. Types of transaction ?
19. What is bean managed transaction ?
20. Why does EJB needs two interface( Home and Remote Interface) ?
21. What are transaction attributes ?
22. What is the difference between Container managed persistent bean and Bean managed persistent entity bean ?
23. What is J2EE ?
24. What is JTS ?
25. How many entity beans used and how many tables can u use in EJB project ?
26. What is scalable,portability in J2EE?
27. What is Connection pooling?Is it advantageous?
28. Method and class used for Connection pooling ?
29. How to deploy in J2EE(i.e Jar,War file) ?
30. How is entity bean created using Container managed entity bean ?
31. Sotware architechture of EJB ?
32. In Entity bean will the create method in EJB home and ejbCreate in Entity bean have the same parameters ?
33. What methods do u use in Servlet - Applet communication ?
34. What are the types of Servlet ?
35. Difference between HttpServlet and Generic Servlets ?
36. Difference between doGet and doPost ?
37. What are the methods in HttpServlet?
38. What are the types of SessionTracking?
39. What is Cookie ? Why is Cookie used ?
40. If my browser does not support Cookie,and my server sends a cookie instance What will happen ?
41. Why do u use Session Tracking in HttpServlet ?
42. Can u use javaScript in Servlets ?
43. What is the capacity the doGet can send to the server ?
44. What are the type of protocols used in HttpServlet ?
45. Difference between TCP/IP and IP protocol ?
46. Why do you use UniCastRemoteObject in RMI ?
47. How many interfaces are used in RMI?
48. Can Rmi registry be written in the code, without having to write it in the command prompt and if yes where?
49. Why is Socket used ?
50. What are the types of JDBC drivers ?
51. Explain the third driver(Native protocol driver) ?
52. Which among the four driver is pure Java driver ?
53. What are the Isolation level in JDBC transaction ?
54. How do you connect with the database ?
55. How do you connect without the Class.forName (" ") ?
56. What does Class.forName return ?
57. What are the types of statement ?
58. Why is preparedStatement,CallableStatement used for?
59. In real time project which driver did u use ?
60. Difference between AWT and Swing compenents ?
61. Is there any heavy weight component in Swings ?
62. Can the Swing application if you upload in net, be compatible with your browser?
63. What should you do get your browser compatible with swing components?
64. What are the methods in Applet ?
65. When is init(),start() called ?
66. When you navigate from one applet to another what are the methods called ?
67. What is the difference between Trusted and Untrusted Applet ?
68. What is Exception ?
69. What are the ways you can handle exception ?
70. When is try,catch block used ?
71. What is finally method in Exceptions ?
72. What are the types of access modifiers ?
73. What is protected and friendly ?
74. What are the other modifiers ?
75. Is synchronised modifier ?
76. What is meant by polymorphism ?
77. What is inheritance ?
78. What is method Overloading ? What is this in OOPS ?
79. What is method Overriding ? What is it in OOPS ?
80. Does java support multi dimensional arrays ?
81. Is multiple inheritance used in Java ?
82. How do you send a message to the browser in JavaScript ?
83. Does javascript support multidimensional arrays ?
84. Why is XML used mainly?
85. Do use coding for database connectivity in XML?
86. What is DTD ?
87. Is there any tool in java that can create reports ?
88. Explain protected vs private vs public data members and methods?
89. Explain overloading and overriding?
90. What is polymorphism?
91. What is inheritance?
92. What is encapsulation?
93. Give an example of where you might use a static method?
94. Explain up casting and down casting?
95. What is an abstract class?
96. Explain multiple inheritance and interfaces?
97. If you have a tree of derived classes, what order are the constructors run
98. How do you deal with errors?
99. What is a ClassLoader?
100. How are ClassLoaders used, when and why?
101. What is a fully qualified class name?
102. What is the classpath, and how does it relate to classloaders?
103. When does the JVM invoke a classloader?
104. When invoked, how does a classloader handle the loading of a class?
105. Can you pass classes between classloader, why/whynot?
106. What is a ClassDefNotFoundError?
107. What is a ClassCastException?
108. What is a CircularityError?
109. How are classes stored in the JVM?
110. Can CORBA be integrated with XML?
111. can I make my site completely safe by running the server in a "chroot" envirinment?
112. Whats the "chroot" environment?
113. How can I detect if my site's been broken into?
114. what types of access restrictions are avilable?
115. Isn't there a CGI Script to allow users to change their passwords online?
116. What are: SSL, SHTTP, Shen? and Cybercash, SET and Open Market?
117. Are there any "freeware" secure services?
118. Can I use Personal Certificates to control server access?
119. What are Perl taint checks? How do I turn them On?
120. How do I untaint a variable?
121. How can you push data from an Applet to Servlet ?
122. How you can know about drivers and database information ?
123. If you are truncated using JDBC, How can you know ..that how much data is truncated ?
124. And What situation , each of the 4 drivers used ?
125. 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 ? Suppose server object is not loaded into the memory, and the client request for it , what will happen?
126. Can you load the server object dynamically? If so, what are the major 3 steps involved in it ?
127. What is difference RMI registry and OSAgent ?
128. What is the corresponding Layout for Card in Swing ?
129. What is light weight component ?
130. Can you run the product development on all operating systems ?
131. What is difference in between Java Class and Bean ?
132. Can we send object using Sockets ?
133. How to communicate 2 threads each other ?
134. What are the files generated after using IDL to Java Compilet ?
135. Can I modify an object in CORBA ?
136. What is the functionality stubs and skeletons ?
137. What is the mapping mechanism used by Java to identify IDL language ?
138. Suppose If we have variable ' I ' in run method, If I can create one or more thread each thread will occupy a separate copy or same variable will be shared ?
139. In servlets, we are having a web page that is invoking servlets username and password ? which is cheks in the database ? Suppose the second page also If we want to verify the same information whethe it will connect to the database or it will be used previous information?
140. What are session variable in Servlets ?
141. How will you pass parameters in RMI ? Why u serialize?
142. What is the exact difference in between Unicast and Multicast object ? Where we will use ?
143. What is the main functionality of the Remote Reference Layer ?
144. How do you download stubs from a Remote place ?
145. I want to store more than 10 objects in a remote server ? Which methodology will follow ? What is meant by Session ? Tell me something about HTTPSession Class ?
146. Have you used threads in Servelet ?
147. How do you sing an Applet ?
148. In a Container there are 5 components. I want to display the all the components names, how will you do that one ?
149. Why there are some null interface in java ? What does it mean ? Give me some null interfaces in JAVA ?
150. Tell me the latest versions in JAVA related areas ?
151. What is meant by class loader ? How many types are there? When will we use them ?
152. How do you load an Image in a Servlet ?
153. What is meant by flickering ?
154. What is meant by distributed Application ? Why we are using that in our applications ?
155. What is the functionality of the stub ?
156. What is the latest version of JDBC ? What are the new features are added in that ?
157. What is the role of the webserver ?
158. What is meant by cookies ? Explain ?
159. How OOPS concept is achieved in Java
160. How does Java 2.0 differ from Java 1.0
161. What are command line arguments
162. Wrapper class. Is String a Wrapper Class
163. What are the restriction for static method
164. Purpose of the file class

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