Interview Questions Answers in JDBC, Core Java, Servlets, Advanced Java, EJB

Question { 6969 }

Different statements in JDBC?

Answer

Hi...
The different statements in JDBC:
1:Simple statement
2:PreparedStatement
3:CallableStatement

Is This Answer Correct ?

3 Yes

2 No

Question { Infosys, 75238 }

How java is platform independent?

Answer

Hi... Java is a platform independent language.After
compiling the ".java" file ,that will be converting into
the ".class" file,which is a byte code having the
capability run on any OS.Basing on the concept byte code
java achieving the platform independent,it leads to "Write
onece run anyware".

Is This Answer Correct ?

196 Yes

54 No

Question { 5735 }

heavy components means what?

Answer

Hi...
Heavy components means , the components that are fully
dependent on underlaying OS.
Example:Applet

Is This Answer Correct ?

0 Yes

0 No

Question { Siemens, 13826 }

What is servlet?

Answer

Hi...
Servlet is a java-web application component that extends
the Generic servlet or HttpServlet classes.Servlet runs in
web server.

Is This Answer Correct ?

2 Yes

0 No

Question { Infogain, 21080 }

what is callable statement?

Answer

Hi... CallableStatement : It is an interface in JDBC
API,which can be used to calling the storedprocedures and
functions in backend like oracle,sybase.

Syntax:
CallableStatement cst=con.prepareCall("{call name>(?,?)}");

Is This Answer Correct ?

34 Yes

6 No

Question { HCL, 40232 }

What is the use of Class.forName

Answer

Hi...
Class.forName();method facilitates you to loading the
driver inorder to providing the connection between the
forntend and backend for database transactions.

Is This Answer Correct ?

2 Yes

15 No

Question { Wipro, 73406 }

What is the difference between a stub and a skeleton?

Answer

Hi...
STUB: Stub is a client side proxy,the purpose of stub is
marshalling the data.
Marshalling: It is the process of converting the java code
(source code) into network oriented stream(bit-blobs stream)
SKELETON: Skeleton is a server side proxy,the purpose of
skeleton is converting the network oriented stream into
java program(human readable formate)
To generate stubs and skeletons we can use "rmic" tool in
JDK.

Is This Answer Correct ?

114 Yes

29 No

Question { 6100 }

What is the relationship between an EJB component, EJB
container, and an application server?

Answer

Hi...
Actually the Application server gives the services to the
EJB Container,the EJB Container provides the run-time
environment for the EJB Conponent,EJB Component full fill
the client request.

Is This Answer Correct ?

1 Yes

0 No

Question { 9176 }

How does JDBC differ from ODBC?

Answer

Hi...
JDBC: It is developed in pure java language.But ODBC
develop in C/C++ language using pointers,it is a microsoft
product.

Is This Answer Correct ?

2 Yes

0 No

Question { 12134 }

what is a package?

Answer

Hi...
A package is nothing but collections of classes and
interfaces.
example:java.lang,java.util,java.applet,java.awt,java.net,ja
va.io etc...

Is This Answer Correct ?

3 Yes

0 No

Question { Honeywell, 12978 }

which method is used to know the status of the Thread?

Answer

Hi... we can use public void isAlive();

Is This Answer Correct ?

4 Yes

1 No

Question { IBM, 23536 }

what exactly happens when we execute
"Class.forname("Driver class name");"?Explain indetail

Answer

Hi... Actually whenever the JVM encounter the statement
Class.forName("Driver class name");The drivers will be
loading into the memory,then only the JVM will identify the
driver to process the database stuff.

Is This Answer Correct ?

2 Yes

1 No

Question { TCS, 22622 }

what is the difference between equals method and ==

Answer

Hi...
"equals()" method always compares the content of an
object,but "==" operator compares the memory locations
(references).
eg: String s1="KOTAGUDIBANDA";
Where "s1" is a reference and "KOTAGUDIBANDA"is a content.

Is This Answer Correct ?

6 Yes

6 No

Question { iGate, 54357 }

when to use abstract class and when to use interface?

Answer

Hi...
When u want to inherit the properties of base class only
(not other resources) go for Abstract class.
When u want to inherit the properties of base class and
other resources go for Interfaces .

Is This Answer Correct ?

42 Yes

34 No

Question { HCL, 80943 }

what is difference between class and object?

Answer

Hi... Class is a blue print of an object,which is non-live
entity.
Object is instance of class,which is a live entity.

example: Employee is a class
Fruit is a class
but
DEVARATHNAM is an object
ROSE is an object

Is This Answer Correct ?

99 Yes

39 No

devarathnam c,kotagudiban