Example of Exchanger in Java

package com.concretepage;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Exchanger;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class ExchangerTest {
          Exchanger<List<String>> exchanger = new Exchanger<List<String>>();
	  List<String>  exchnagerList= new ArrayList<String>();
	   class AddList implements Runnable {
	     public void run() {
	       try {
	         while (true) {
	           exchnagerList.add("1");
	           if (exchnagerList.size()==1){
	        	   exchnagerList = exchanger.exchange(exchnagerList);
	        	   
	           }
	         }
	       } catch (InterruptedException ex) { System.out.println(ex); }
	     }
	   }
	   class SubtractList implements Runnable {
	     public void run() {
	       try {
	         while (true) {
	        	 exchnagerList.remove("1");
	        	 if (exchnagerList.size()==0){
	        	   exchnagerList = exchanger.exchange(exchnagerList);
	        	   
	                 }
	         }
	       } catch (InterruptedException ex) { System.out.println(ex);}
	     }
	   }
	   public static void main(String... args) {
		   final ExecutorService exService = Executors.newFixedThreadPool(2);
		   ExchangerTest ob = new ExchangerTest();
		   exService.execute(ob.new SubtractList());
		   exService.execute(ob.new AddList());
	   }
}