check if hashtable contains key in java

/**
 * @author lautturi.com
 * Java example: java determine whether hashtable contains a key 
 */

import java.util.*;
import java.util.Map.Entry;

public class Lautturi {

	public static void main(String[] args) {
		
		Hashtable<Integer,String> hash_tab=new Hashtable<Integer,String>(); 

		hash_tab.put(5,"Apple");
		hash_tab.put(7,"Banana");
		hash_tab.put(12,"Cherry");
		hash_tab.put(33,"Orange");
		hash_tab.put(23,"Lautturi");

		if(hash_tab.containsKey(33)) {
			System.out.println("The hash table contains the key 33");
		}
		if(!hash_tab.containsKey(34)) {
			System.out.println("The hash table does not contain the key 34");
		}

	}
}

output:

The hash table contains the key 33
The hash table does not contain the key 34