Limit the number of objects being created in JAVA

Q   :- Limit the number of objects being created in JAVA.

Sol :- The example below limits creation of objects of MyClass class to a maximum of 5 by declaring the constructor private and calling it via getMyClass() method.If an attempt to create more than 5 objects is done, the getMyClass() method will return a null,thus,the object so created will not be referenced and ultimately cleared by the garbage collector.

 

import java.io.*;

class MyClass

{

public static int count=0;

int a;

private MyClass()

{

count++;

a=count;

System.out.println("object created  = "+a);

if(count>4)

System.out.println("Object Creation Limit Exceeded");

}

public static MyClass getMyClass()

{

if(MyClass.count==5)

return null;

else

return new MyClass();

}

}

class LimitObjectInstance

{

public static void main(String [] args)

{

int i=-1,ch;

BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); 

MyClass obj[]=new MyClass[10];

while(true)

{

System.out.println("\nDo you want to create new Object (1 for Yes ) ??   ");

try

{

ch=Integer.parseInt(br.readLine()) ;

}

catch(Exception e)

{

ch=2;

}

if(ch==1)

{

i++;

                   obj[i]= MyClass.getMyClass();

}

else

{

System.exit(0);

}

}

}

}