Inner Class: An example

[Ashik Uzzaman]

Hi ranchers,
Regarding the difference between Top-level Nested class (now known as Static Inner Class) & Non-static Inner Class and how they are inherited from another class, i have prepared a code that may give u chance to play around and improve it. I intentionally made the code longer and JavaBeans compliant!

//Outer class SCJP
public class SCJP
{
private int score;
private final static int passingScore;
private boolean pass;
//static initializer expression
static
{
passingScore = 61;
}
SCJP()//default constructor is must for a JavaBeans compliant class.
{
score = 75;//this part is to be implemented in Database
if(score >= passingScore)
pass = true;
else
pass = false;
}
public int getScore()//getter() [accessor]
{
if(pass)
System.out.println("Congratulations, you have passed with "+this.score+"% marks.");
else
System.out.println("Sorry, you have failed with "+score+"% marks.");
return score;
}
public void setScore(int score)//setter() [mutator]
{
this.score = score;
}
//Top-level nested class
private static class QFormat extends SCJP implements java.io.Serializable
{
private final int numOfQs;
{
numOfQs = 59;
}//non-static initializer
QFormat()
{
System.out.println("QFormat");
}
public int getNumOfQs()
{
System.out.println("You have "+numOfQs+" questions in this test.");
return numOfQs;
}
}//end of static inner class.
private class User extends QFormat implements java.io.Serializable
{
private String name;
public String getName()
{
System.out.println("Your name is :\t"+name);
return name;
}
public void setName(String name)
{
this.name = name;//Variable shadowing
}
public User()
{
System.out.println("User");
}
}//end of non-static inner class.
public static void main(String[] args)
{
SCJP outer = new SCJP();
outer.getScore();
SCJP.QFormat staticInner = new SCJP.QFormat();
System.out.println(staticInner.getNumOfQs());
SCJP.User nonStaticInner1 = new SCJP().new User();
 SCJP.User nonStaticInner2 = outer.new User();
nonStaticInner1.setName("Ashik");
String nameHere = nonStaticInner1.getName();
System.out.println(nameHere);
System.out.println(nonStaticInner2.getName());
/**
 [B]SCJP.User nonStaticInner3 = this.new User();[/B]
It would also be another way of generating a non-static inner class object but here we 
are under main method where there is no "this" reference. 
*/
}
}

Hope you have fun with it...