Java class instantiation procedures.

-------------Jave class------------

public class House {

static int numOfPillars = 4;

private int numOfMembers = 6;

private String nameOfHouse = "The Hom's family";

public House() {

System.out.println(this.getClass().getSimpleName() + " constructor called");

}

}

static fields are initialised when the class is first loaded. 

1. House.<clinit>() method is called, initialise static fields, in this case: numOfPillars;

2. House.<init>() method is called, initialise non-static fields, such as numOfMembers, nameOfHouse;

3. and then House.<init>() calls the constructor public House(){}

Typical class initiation
----------Bytecode Level----------------

 new           #16                 // class Subclass

 dup           

 invokespecial #18                 // Method Subclass."<init>":()V

 astore_2      

new - create new object of type identified by class reference in constant pool index, in this case #16

the duplicate the return value of 'objectref'

invokespecial method consumes one of the two 'objectref' in the stack, calling the <init> method of the class.

and then stores the rest 'objectref' into local variable table