Question:

View: a class with one field private List models

and $3$ methods:

public void Attach$($Model m$)$

public void Detach$($Model m$)$

public void Notify$($int s$)$

ConcreteView: a class inheritents from View,

one field

private int state $=0$;

and two methods:

public int GetState$()$

public void SetState$($int s$)$

Model: an abstract class with one abstract method:

public abstract void Update$($int s$)$;

ConcreteModel: a class inheritents from Model.

two fields

private int state;

private ConcreteView view;

one method

public void Update$($int s$)$

Task: finish implementing the code and run the main method below.

public static void main$($String$[]$ args$)\{$

$//$ TODO Auto$-$generated method stub

Random r $=$ new Random$()$;

int max $=100$;

int min $=0$;

View v $=$ new ConcreteView$()$;

Model m$1=$ new ConcreteModel$(352,$ v$)$;

v$.$Attach$($m$1)$;

for$($int i $=0$; i $<10$; i$++)\{$

int temp $=$ r$.$nextInt$(($max$-$min$)+1)+$min;

Model m $=$ new ConcreteModel$($temp$,$ v$)$;

v$.$Attach$($m$)$;

$\}$

List models $=$ v$.$getModels$()$;

System.out.println$("$Size of models $"+$models.size$())$;

v$.$Detach$($ m$1)$;

System.out.println$("$Size of models after delection $"+$models.size$())$;

v$.$Notify$($max$)$;

ConcreteView v$2=($ConcreteView$)$ v;

System.out.println$("$Current State is $"+$v$2.$GetState$())$;

$\}$

Sample Output:

Size of models $11$

Size of models after delection $10$

Current State is $100$