Classic Producer-Consumer problem rehashed

RoomProblem.java

/* The Classic Producer-Consumer problem rehashed
 * 
 * “There is a room with many people in it. People can enter and exit the room at any time. 
 *  Write a program to find the number of people in the room at any given time.”
 */
class Room {
	private int count; //head count
	private boolean isFull; 
	private int capacity; 
	
	public Room(int capacity)
	{	
	  isFull = false;
	  count = 0;
	  this.capacity = capacity;
	 }	
	
	public synchronized int enterRoom() 
	{
		while(isFull==true) // if room is full, then wait
		{
			try
			{
				wait();
			}catch(InterruptedException ex){}
		} //enter the room and increment the count
		count++;
		if(count>=capacity) //if the room is full, put the house full board :)
		{
			isFull=true;
			notifyAll();
		}
		return count;
	}
	public synchronized int exitRoom()
	{
		while(isFull==false) // no one can exit an empty room!
		{
			try
			{
				wait();
			}catch(InterruptedException ex){}
		}
		count--;
		if(count==0)
		{
			isFull = false;
			notifyAll();
		}
		return count;
	}
}

class Enter extends Thread // Analogous to Producer 
{
	private Room room;
	private int iterations;
	
	public Enter(String name, int iterations, Room room)
	{
		super(name);
		this.room = room;
		this.iterations = iterations;
	}
	
	public void run()
	{
		for(int i=0;i<iterations;i++)
		{
			int headCount = room.enterRoom();
			System.out.println(this.getName()+"\t\tHead count: " + headCount);
			
			try 
			{
				Thread.sleep((long)(Math.random()*1000)); // people enter & exit the room in random intervals
			} catch (InterruptedException e) {}
		}
	}
}


class Exit extends Thread // Analogous to Consumer 
{
	private Room room;
	private int iterations;
	
	public Exit(String name, int iterations, Room room)
	{
		super(name);
		this.room = room;
		this.iterations = iterations;
	}
	
	public void run()
	{
		for(int i=0;i<iterations;i++)
		{
			int headCount = room.exitRoom();
			System.out.println(this.getName()+"\t\tHead count: " + headCount);
			
			try 
			{
				Thread.sleep((long)(Math.random()*1000)); 
			} catch (InterruptedException e) {}
		}
	}
}

public class RoomProblem 
{
	public static void main(String args[])
	{
		int size = (int)(Math.random()*20)+1; // a random room size. Adding 1 to prevent the room size being 0
		System.out.println("Room capacity: "+size);
		System.out.println();
		Room room = new Room(size);
		Enter ent1 = new Enter("Entering Door 1",size,room); // The size parameter passed here
		Enter ent2 = new Enter("Entering Door 2",size,room); // is just the number of times people can 
		Exit ext1 = new Exit("Exiting Door 1",size,room);   // enter/exit. For convenience I've set it to the 
		Exit ext2 = new Exit("Exiting Door 2",size,room);  // capacity of the room. As per the original problem this
		ent1.start();					  // is infinity. 
		ext2.start();
		ent2.start();
		ext1.start();
	}
}

Sample Output:

Room capacity: 15

Entering Door 1 Head count: 1
Entering Door 2 Head count: 2
Entering Door 1 Head count: 3
Entering Door 1 Head count: 4
Entering Door 2 Head count: 5
Entering Door 2 Head count: 6
Entering Door 2 Head count: 7
Entering Door 1 Head count: 8
Entering Door 1 Head count: 9
Entering Door 1 Head count: 10
Entering Door 2 Head count: 11
Entering Door 1 Head count: 12
Entering Door 2 Head count: 13
Entering Door 1 Head count: 14
Entering Door 2 Head count: 15
Exiting Door 2 Head count: 13
Exiting Door 1 Head count: 14
Exiting Door 2 Head count: 12
Exiting Door 1 Head count: 11
Exiting Door 2 Head count: 10
Exiting Door 1 Head count: 9
Exiting Door 2 Head count: 8
Exiting Door 2 Head count: 7
Exiting Door 1 Head count: 6
Exiting Door 2 Head count: 5
Exiting Door 1 Head count: 4
Exiting Door 2 Head count: 3
Exiting Door 2 Head count: 2
Exiting Door 1 Head count: 1
Entering Door 2 Head count: 1
Exiting Door 1 Head count: 0
Entering Door 1 Head count: 2
Entering Door 2 Head count: 3
Entering Door 1 Head count: 4
Entering Door 2 Head count: 5
Entering Door 1 Head count: 6
Entering Door 2 Head count: 7
Entering Door 1 Head count: 8
Entering Door 2 Head count: 9
Entering Door 2 Head count: 10
Entering Door 1 Head count: 11
Entering Door 2 Head count: 12
Entering Door 2 Head count: 13
Entering Door 1 Head count: 14
Entering Door 1 Head count: 15
Exiting Door 2 Head count: 13
Exiting Door 1 Head count: 14
Exiting Door 2 Head count: 12
Exiting Door 1 Head count: 11
Exiting Door 2 Head count: 10
Exiting Door 1 Head count: 9
Exiting Door 2 Head count: 8
Exiting Door 2 Head count: 7
Exiting Door 1 Head count: 6
Exiting Door 2 Head count: 5
Exiting Door 1 Head count: 4
Exiting Door 1 Head count: 3
Exiting Door 2 Head count: 2
Exiting Door 1 Head count: 1
Exiting Door 1 Head count: 0