Java Collection - 如何遍历HashMap的值

import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;

public class Main {

  public static void main(String[] args) {
    HashMap<String, String> hMap = new HashMap<String, String>();
    hMap.put("1", "One");
    hMap.put("2", "Two");
    hMap.put("3", "Three");

    Collection c = hMap.values();
    Iterator itr = c.iterator();
    while (itr.hasNext()) {
      System.out.println(itr.next());
    }
  }
}