Java WeakHashMap() Constructor

public WeakHashMap()

//from   www  .j  a v  a 2  s .  c  om
import java.util.Collection;
import java.util.Map;
import java.util.WeakHashMap;

public class Main {
   public static void main(String[] args) { 
      Map<String, String>  weakHashMap = new WeakHashMap<String, String> ();
            
      
      System.out.println("Putting values into the Map");
      weakHashMap.put("1", "first");
      weakHashMap.put("2", "two");
      weakHashMap.put("3", "from java2s.com");
      
      // checking the size of the Map
      System.out.println("Map values: "+weakHashMap);  
      
      Collection col = weakHashMap.values();
      System.out.println("Collection values: "+col);  
   }      
}