Effective classes of Java learning notes that cannot be instantiated

When you do not explicitly declare a class's construction method, the compiler generates a default parameterless construction method, and when you design a tool class, we usually set the method to a static method. Called in the form of the class name. Method name, at this point there is no need to create an instance of the class, we know that the abstract class can not be instantiated, but it can be the Quilt class inheritance, subclasses can be instantiated, to think of a class cannot be instantiated, only need to explicitly set the class's construction method to private domain, so it can not be instantiated by the method of the external class, and the subclass Inheriting constructor methods are private parent classes

 Package com.test;  Public class Nochildclass {    private  Nochildclass () {}}

The class cannot be instantiated in another class and cannot be inherited by a quilt class

Effective classes of Java learning notes that cannot be instantiated