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 java and c++?
5.) In an htm form I have a button which makes us to open another page in 15 seconds. How will you do that?
6.) What is the difference between process and threads?
7.) What is update method called?
8.) Have you ever used HashTable and Directory?
9.) What are statements in Java?
10.) What is a JAR file?
11.) What is JNI?
12.) What is the base class for all swing components?
13.) What is JFC?
14.) What is the difference between AWT and Swing?
15.) Considering notepad/IE or any other thing as process, What will happen if you start notepad or IE 3 times ? Where three processes are started or three threads are started?
16.) How does thread synchronization occur in a monitor?
17.) Is there any tag in htm to upload and download files?
18.) Why do you canvas?
19.) How can you know about drivers and database information ?
20.) What is serialization?
21.) Can you load the server object dynamically? If so what are the 3 major steps involved in it?
22.) What is the layout for toolbar?
23.) What is the difference between Grid and Gridbaglayout?
24.) How will you add panel to a frame?
25.) Where are the card layouts used?
26.) What is the corresponding layout for card in swing?
27.) What is light weight component?
28.) Can you run the product development on all operating systems?
29.) What are the benefits if Swing over AWT?
30.) How can two threads be made to communicate with each other?
31.) What are the files generated after using IDL to java compiler?
32.) What is the protocol used by server and client?
33.) What is the functionability stubs and skeletons?
34.) What is the mapping mechanism used by java to identify IDL language?
35.) What is serializable interface?
36.) What is the use of interface?
37.) Why is java not fully objective oriented?
38.) Why does java not support multiple inheritance?
39.) What is the root class for all java classes?
40.) What is polymorphism?
41.) Suppose if we have a 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?
42.) What are virtual functions?
43.) Write down how will you create a Binary tree?
44.) What are the traverses in binary tree?
45.) Write a program for recursive traverse?
46.) What are session variable in servlets?
47.) What is client server computing?
48.) What is constructor and virtual function? Can we call a virtual function in a constructor?
49.) Why do we use oops concepts? What is its advantage?
50.) What is middleware? What is the functionality of web server?
51.) Why is java not 100% pure oops?
52.) When will you use an interface and abstract class?
53.) What is the exact difference in between Unicast and Multicast object? Where will it be used?
54.) What is the main functionality of the remote reference layer?
55.) How do you download stubs from Remote place?
56.) I want to store more than 10 objects in a remote server? Which methodology will follow?
57.) What is the main functionality of Prepared Statement?
58.) What is meant by Static query and Dynamic query?
59.) What are Normalization Rules? Define Normalization?
60.) What is meant by Servelet? What are the parameters of service method?
61.) What is meant by Session? Explain something about HTTP Session Class?
62.) In a container there are 5 components. I want to display all the component names, how will you do that?
63.) Why there are some null interface in JAVA? What does it mean? Give some null interface in JAVA?
64.) Tell some latest versions in JAVA related areas?
65.) What is meant by class loader? How many types are there? When will we use them?
66.) What is meant by flickering?
67.) What is meant by distributed application? Why are we using that in our application?
68.) What is the functionality of the stub?
69.) Explain about version control?
70.) Explain 2-tier and 3-tier architecture?
71.) What is the role of Web Server?
72.) How can we do validation of the fields in a project?
73.) What is meant by cookies? Explain the main features?
74.) Why java is considered as platform independent?
75.) What are the advantages of java over C++?
76.) How java can be connected to a database?
77.) What is thread?
78.) What is difference between Process and Thread?
79.) Does java support multiple inheritance? if not, what is the solution?
80.) What are abstract classes?
81.) What is an interface?
82.) What is the difference abstract class and interface?
83.) What are adapter classes?
84.) what is meant wrapper classes?
85.) What are JVM.JRE, J2EE, JNI?
86.) What are swing components?
87.) What do you mean by light weight and heavy weight components?
88.) What is meant by function overloading and function overriding?
89.) Does java support function overloading, pointers, structures, unions or linked lists?
90.) What do you mean by multithreading?
91.) What are byte codes?
92.) What are streams?
93.) What is user defined exception?
94.) In an htm page form I have one button which makes us to open a new page in 15 seconds. How will you do that?