Question { Wipro, 18447 }

what is singleton class? where it mainly used in the
projects?

Answer

singleton means create the one and only object per class
that per jvm

---use to decrese globel variables
---to provide the encapsulation

Question { TCS, 26714 }

what is java bean?where can we use it?

Answer

javabean is encapsulate data in the form of
object.according to java specification javabean support any
number of properties and any number of events and
additional mthods..

Question { IBM, 19732 }

In web.xml file instead of *.do can i write *.ibm, Specify
with example

Answer

yes,but it can't recomendes most of the cases we must
prefer *.do as good programer

Question { 14593 }

Can i use constructor in Action Class?If yes how?

Answer

ActioClass is on of the servet and it is superclass of
javax.servlet.HTTP.HTTPServlet.In the servet there is
possiblity of write zeroorgumen consrtacter but can't write
perametarised cunstracter becouse of perametarised
constrater can't read container...

Question { Wipro, 24873 }

why Runnable interface is preferable than extending the
Thread class?

Answer

imolimen Runnabule inerface and extends Thread functionally
both are same.But implimenting RunnebleInterface more
advantage because of there is possibility extends more then
one class and also we can override run() only once.