Simple Java Hashtable Example

public class SimpleHashtableExample

   {

     public static void main(String[] args)

     {

       //create object of Hashtable

       Hashtable ht = new Hashtable();

      

       /*

       Add key value pair to Hashtable using

       Object put(Object key, Object value) method of Java Hashtable class,

       where key and value both are objects

       and can not be null.

       put method returns Object which is either the value previously tied

       to the key or null if no value mapped to the key.

       */

      

       ht.put("One", new Integer(1));

       ht.put("Two", new Integer(2));

      

       /*

       Please note that put method accepts Objects. Java Primitive values CAN NOT

       be added directly to Hashtable. It must be converted to corrosponding

       wrapper class first.

       */

      

       //retrieve value using Object get(Object key) method of Java Hashtable class

       Object obj = ht.get("One");

       System.out.println(obj);

      

       /*

       Please note that the return type of get method is Object. The value must

       be casted to the original class.

       */

     }

   }