sure why not if we are not provide a constuctor for servlet 
it automatically get constructor by the java compiler if we 
provide a constuctor for a servlet the java compiler will 
not provide constuctor at that situation

yes we can create constructor of servlet instead of init 
method but i dont get servlet specification answers.

yes ofcourse we should.
it is mandatory for servlet.
for servlets we required publc no argument constructor. if v
don't having that one, our servlet should not work, even
though if you are not crating the public no-argument
constructor, the java compiler will take the responsibility
to create public no- argument constructor.. mean while your
servlet should be public otherwise you will get
RuntimeException.


we can create costructor for sevelet but it should b no-
argument constructor. and u r servlet should be public. 
and one more thing this constructor in not in the place of
init() method..