Java Interview Questions

Exception is nothing but error but some difference whenever exception will raise program can execute continuously where as error program will not execute

An exception is a condition that is caused by a run time error in the program .When the java interpreter encounters an error like division by zero,it creates an exception object and throws it.

Those are variables static can be defined where the variable is constant,instance variable can be defined instance of class object

1) An instance variable is one whose memory space is creating each and every time whenever an object is created. 1) Static variables are whose memory space is creating only once when the class is load...

first of it will not compile,because outer classes we cant create with the modifier protected

Class will only be public,default,final
protected & private yield to compile time error

b) Compiles and prints Technologies

Answer is a.

Static variables value can be change by only static method . Here, Run is not a static method so the value of variable msg can not change.

Sleep and yields methods are static .Please refer given below doc for the explanation.
http://docs.oracle.com/javase/1.4.2/docs/api/java/lang/Thread.html

(a)sleep (c)start

transient is a keyword....If a variable is declared as a Transient ,we cant serialize that variable.. The important points about Transient are: 1) Transient keyword can only be applied to fields or ...

A transient variable is a variable that may not be serialised.

the left operand is an object reference or null vale
the right operand is a cla,interface,or aaray type

The legal operands of instance of operator are
1. Left operand which is an object reference.
2. Right operand which can be a class or an interface.

Compile Time Error..

Compile Time Error

Unicast v/s multicast difference in proper format in networking

Orange

Answer is B. Orange

Static block always executed before invoking the main method. here, we are creating object of class W. So, it will print Orange

Both a & b

a & b

a) is the correct answer because a class firstly extends another class & then implements interface.

1. If you are creating something that provides common functionality to unrelated classes, use an interface.

2. If you are creating something for objects that are closely related in a hierarchy, use an abstract class.

If you want common functionality(generalization) for some classes go for abstract
If you dont want generalization then go for abstract class

Finalization is a facility provided by Java for classes who use native resources to clean up before the objects are garbage collected. Since native resources or allocations are beyond the control of ...

The purpose of finalization is to give an unreachable object the opportunity to perform any cleanup processing before the object is garbage collected.

Yes.

Using of the validation framework we can do the form validations. Struts provides ready made validation. Using of the validation.xml file we can do the form validation.


Second approaches is using javascript.

Session is nothing but a small amount of data that is storing at server side. We can handle sessions in different approaches.

1. HttpSessions
2.Cookies.
3.URL Rewriting.
4.Hidden Form..


Using of HttpSessions we can store the information is server side. Its available to till session expire.

We declare, main method in java as : public static void main(String args[]) public : means it can be accessible to all other classes. static : main is the entry point of a class. In java everythin...

We declare, main method in java as : public static void main(String args[]) public : means it can be accessible to all other classes. static : main is the entry point of a class. In java everythin...

I think your first option is true. But any how these things depends on access specifiers. If you are not specifying any access specifier default package level access will be applied to the classes, wh...

We can implements SingleThreadModel in Servlets Class.

Code
import javax.servle*.;
public class Simple implements SingleThreadModel
{
  }

Servlets dont run in their own threads. Instead, when a request comes in, the app server removes a thread from a master thread pool and uses it to drive the servlets service method. Once the service method has returned, the thread is returned to the thread pool.

Finally block having the statements which are releasing the resource, closing the streams, closing the connection and so on. If exception is raised or not but closing the resource are necessary. So we can keep statements inside the finally block those should be get executed compulsory.

Finally is the block which will be executed irrespective of exception caught in catch block.
Hence it is useful to do any resource releasing/ connection closing after exception handling