can we write a parameterized constructor in servlet class or not?

A web container creates a servlet class object by calling the newInstance() method .

NewInstance() method checks for the fallowing 

a)A class is public or not

b)A class contain default constructor not.

If we write only parameterized constructer in a servlet then it does’t contain a default constructor then the program will not be executed.

If we write a parameterized constructor and default constructor then servlet is valid  and it’s object is created by the web container by calling the newInstance()