package jbohn.thread;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;

public class JConcurentException
{
 private static final HashMap<Integer, String> maps = new HashMap<Integer, String>();

 public static void main(String[] args) {

  maps.put(new Integer(1), "Hello America");
  maps.put(new Integer(2), "Hello Africa");
  maps.put(new Integer(3), "Hello Asia");
  maps.put(new Integer(4), "Hello Europe");

  //Using thread t1 for traverser keySet of maps
  Thread t1 = new Thread(new Runnable() {
   @Override
   public void run()
   {
    Set<Integer> keySet = maps.keySet();
    for (Iterator iterator = keySet.iterator(); iterator.hasNext();) {
     Integer integer = (Integer) iterator.next();
     System.out.println("Key: " + integer);
    }
   }
  });
  t1.start();

  //Update maps in other thread
  Thread t2 = new Thread(new Runnable() {
   @Override
   public void run()
   {
    maps.remove(new Integer(2));
   }
  });
  t2.start();
 }
}