Constructors are meant to be public.
Why should we make them private?
Let's check the cases where we should consider creating private constructor
Case 1: For Singleton design pattern
A singleton is a design pattern that allows only one instance of your class to be created, and this can be accomplished by using a private constructor.
Case 2: When creating an object doesn't make sense
This occurs when :
- the class only contains static members, those members can be accessed using only the class name
- no instance of the class needs to be created
Java always provides a default, no-argument, public constructor if no programmer-defined constructor exists. Creating a private no-argument constructor essentially prevents the usage of that default constructor, thereby preventing a caller from creating an instance of the class.
Note that the private constructor can be empty.
