public class Static2 {
 
 
    private String _mood = _HAPPY;
 
  
  private final static String _HAPPY   = "happy";
   
 private final static String _ANNOYED = "annoyed";
 
   private final static String _ANGRY   = "angry";
 
 
   private static int _instantiations;
 
  
  public static void main( String [] args ) {
   
     
Static2 obj1 = new Static2();
 
 
Static2 obj2 = new Static2();
 
obj1.printMood();
obj2.printMood();
 
obj1.receiveHug();
obj2.receivePinch();
 
obj1.printMood();
obj2.printMood();
 
    }
    
    
    public Static2() {
        _instantiations++;
    }
 
    public static int instances() {	
        return _instantiations;
    }
 
    public void printMood() {
        System.out.println( "I am " + _mood );
    }
 
    public void receivePinch() {
        if( _mood.equals( _HAPPY ) ) {
            _mood = _ANNOYED;
        } else {
            _mood = _ANGRY;
        }
    }
 
    public void receiveHug() {
        if( _mood.equals( _ANGRY ) ) {
            _mood = _ANNOYED;
	} else {
            _mood = _HAPPY;
        }
    }
}

.
.
.
System.out.println(Static2.instances()); //output will be "0".
Static2 s1 = new Static2(); //increases the counter
System.out.println(Static2.instances()); //output will be "1"
System.out.println(s1.instances()); //output will be "1"
Static2 s2 = new Static2(); //increases the counter
System.out.println(Static2.instances()); //output will be "2"
System.out.println(s2.instances()); //output will be "2"
System.out.println(s2.instances()); //output will be "2"