Design Patterns Java™ Workbook

Appendix B. Solutions

Introducing Extensions (Chapter 26)......................................................................................................

SOLUTION 26.1....................................................................................................................................

The complete code should look something like:

package com.oozinoz.machine;
import java.util.*;
public class BinStack
{
public static final int STACK_LIMIT = 3;
private Stack stack = new Stack();

synchronized public Bin pop()
{
while (stack.size() == 0)
{
try
{
wait();
Thread.sleep(500);
}
catch (InterruptedException ignore)
{
}
}
if (stack.size() == STACK_LIMIT)
{
notify();
}
return (Bin) stack.pop();
}

synchronized public void push(Bin b)
{
while (stack.size() == STACK_LIMIT)
{
try
{
wait();
Thread.sleep(500);
}
catch (InterruptedException ignore)
{
}
}
if (stack.size() == 0)
{
notify();
}
stack.push(b);
}

public int size()
{
return stack.size();
}
}