Create Java Hashtable from HashMap example

/*
  Create Java Hashtable from HashMap example
  This Java Example shows how to copy all key value pairs from HashMap Object to
  Hashtable Object using putAll method of java Hashtable class.
*/
 
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.HashMap;
 
public class CreateHashtableFromHashMap {
 
  public static void main(String[] args) {
 
    //create HashMap
    HashMap hMap = new HashMap();
 
    //populate HashMap
    hMap.put("1","One");
    hMap.put("2","Two");
    hMap.put("3","Three");
 
    //create new Hashtable
    Hashtable ht = new Hashtable();
 
    //populate Hashtable
    ht.put("1","This value would be REPLACED !!");
    ht.put("4","Four");
 
    //print values of Hashtable before copy from HashMap
    System.out.println("Hashtable contents before copy");
    Enumeration e = ht.elements();
    while(e.hasMoreElements())
      System.out.println(e.nextElement());
 
    /*
      To copy values from HashMap to Hashtable use
      void putAll(Map m) method of Hashtable class.
     
      Please note that this method will REPLACE existing mapping of
      a key if any in the Hashtable
    */
 
    ht.putAll(hMap);
 
    //display contents of Hashtable
    System.out.println("Hashtable contents after copy");
    e = ht.elements();
    while(e.hasMoreElements())
      System.out.println(e.nextElement());
 
  }
}
 
/*
Output would be
Hashtable contents before copy
Four
This value would be REPLACED !!
Hashtable contents after copy
Four
Three
Two
One
*/