How JAVA constructor works

HtmlPhpMySql.java

/*File : Html.java*/
import packages.*;
public class Html extends Php{
	public Html(){
		super();                           /*Parent Constructor Initialization*/
	}
	public static void main(String args[]){
		System.out.println("Welcome to HTML 5");
		Html html= new Html();             /*Self Constructor Initialization*/
	}
}

/*======================File : packages/Php.java======================*/
package packages;
public class Php extends MySql {
	public Php(){
		System.out.println("PHP has been initialized");
	}
}

/*======================File : packages/MySql.java======================*/
package packages;
public class MySql {
	public MySql(){
		System.out.println("MySql has been initialized");
	}
}