Synchronization of two methods which work on a List in Multi Thread Env without ConcurrentCollection

import java.util.ArrayList;

import java.util.List;

import java.util.Random;

import java.util.concurrent.CountDownLatch;

public class SynchronousListItems {

public static void main(String[] args) {

List<Item> items = new ArrayList<>();

CountDownLatch creatorLatch = new CountDownLatch(1);

CountDownLatch sumLatch = new CountDownLatch(1);

int numberOfItemsToCreate = 100;

Thread createrThread = new Thread(new Creator(items, creatorLatch, numberOfItemsToCreate));

createrThread.setDaemon(true);

Sum sumObj = new Sum(items, sumLatch);

Thread sumThread = new Thread(sumObj);

sumThread.setDaemon(true);

createrThread.start();

sumThread.start();

try {

creatorLatch.await();

} catch (InterruptedException e) {

e.printStackTrace();

} finally {

sumObj.setStopSignal(true);

}

try {

sumLatch.await();

} catch (InterruptedException e) {

e.printStackTrace();

}

}

}

class Creator implements Runnable {

private List<Item> items;

private CountDownLatch creatorLatch;

private int numberOfItemsToCreate;

public Creator(List<Item> items, CountDownLatch creatorLatch, int numberOfItemsToCreate) {

this.items = items;

this.creatorLatch = creatorLatch;

this.numberOfItemsToCreate = numberOfItemsToCreate;

}

@Override

public void run() {

Random random = new Random(10L);

while (numberOfItemsToCreate > 0) {

int wage = random.nextInt();

System.out.println(wage);

items.add(new Item(wage));

numberOfItemsToCreate--;

}

creatorLatch.countDown();

}

}

class Item {

private int wage;

public Item(int wage) {

this.wage = wage;

}

public int getWage() {

return wage;

}

}

class Sum implements Runnable {

private boolean stopSignal;

private List<Item> items;

private int total;

private int itemsCounter;

private CountDownLatch sumLatch;

public Sum(List<Item> items, CountDownLatch sumLatch) {

this.items = items;

this.sumLatch = sumLatch;

}

@Override

public void run() {

try {

while (!stopSignal) {

if (items != null && !items.isEmpty() && items.size() > itemsCounter) {

System.out.println("Itemes are not empty");

System.out.println("Itemes Counter " + itemsCounter);

while (itemsCounter < items.size()) {

Item item = items.get(itemsCounter);

System.out.println("Item Pulled");

total = total + item.getWage();

itemsCounter++;

}

}

}

} catch (Exception e) {

e.printStackTrace();

} finally {

System.out.println("Final Items Counter :" + itemsCounter);

System.out.println("Total :" + total);

sumLatch.countDown();

}

}

public void setStopSignal(boolean stopSignal) {

this.stopSignal = stopSignal;

}

}