runningSum

import java.util.Date.*;
import java.util.ArrayList;
 
class runningSum implements Runnable 
{
    private String str;
    private int sum;
	private ArrayList<Integer> numSequence;
	private int currentSum;
	public boolean terminates;
	private long timeRecord;
	private int partialSum;
 
    public runningSum() 
    {
        //str=new String (s);
		numSequence = new ArrayList<Integer>();
		timeRecord = System.currentTimeMillis();
		terminates = false;
		sum = 0;
		partialSum = 0;
    }
 
 
	public void add(int a)
	{
		partialSum = partialSum + a;
	}
 
	public int retrieveV()
	{
		long newTimes = System.currentTimeMillis();
		if (newTimes - timeRecord > 300000)
		{
			return sum;
		}else
		{
			return sum + partialSum;
		}
	}
 
    public void run () 
    {
        for (;;)
		{
			if (terminates)
			{
				break;
			}
			try
			{
				Thread.sleep(5000);
				synchronized (this) {
				  System.out.println("Sum before: " + sum + ", partial before: " + partialSum + ", millis: " + System.currentTimeMillis());
				  sum = sum + partialSum;
				  numSequence.add(new Integer(partialSum));
				  partialSum = 0;
				  while (numSequence.size() > 60)
				  {
					Integer toRemove = (Integer) numSequence.remove(0);
					int temp = toRemove.intValue();
					sum = sum - temp;
 
				  }
				}
			}catch(Exception e)
			{
				System.out.println("Woops:" + e.getMessage());
			}
		}
            System.out.print ("Finished...");
    }
 
	public static void main(String args[])
	{
		try{
			runningSum sumA = new runningSum();
			(new Thread(sumA)).start();
			for (int i = 0; i < 100; i++)
			{
				sumA.add(100);
				Thread.sleep(15000);
				System.out.println("Sum is:" + sumA.retrieveV() + ", millis: "  + System.currentTimeMillis());
			}
			sumA.terminates = true;
		}catch(Exception e)
		{
			System.out.println("Woops");
		}
	}
}