March 24, 2009 at 3:48 AM
public A() constructor is globally accessible. It can be accessed not only within the class but also outside the class.
private A() constructors can be instantiated within the class and
prevent a class from being explicitly instantiated outside the class.
protected A() constructor is used within the class. It can be accessed by the subclasses.
The Access specifiers allows to group related classes together in a package so that they can easily interact with each other.