<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">package observer;

public class ObserverTest implements Observer&lt;Character&gt; {

   private char c;
   
   public static void main(String[] args) {
   
      ObserverTest ot1 = new ObserverTest('a');
      ObserverTest ot2 = new ObserverTest('b');
      ObserverTest ot3 = new ObserverTest('c');
      Observable&lt;Character&gt; obs = new Observable&lt;Character&gt;() {};
      obs.addObserver(ot1);
      obs.addObserver(ot2);
      obs.addObserver(ot3);
      obs.changed = true;
      obs.notifyObservers('X');

   }
   
   ObserverTest(char c) {
      this.c = c;
   }

   public void update(Character event) {
      System.out.format("%c%c\n", c, event);
   }

}
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