21. Example: interrupting a thread

• 
  import java.util.Scanner;
  
  public class Main {
      public static void main(String[] args) {
          System.out.println(
              "Press the Enter key to stop counting:" );
          Thread counter = new Thread( new Counter() );
  
          // start the counter thread
          counter.start();         
          Scanner sc = new Scanner( System.in );
          String str = "start";
  
          // wait for the user to press Enter
          while ( !str.equals("") ) {     
              str = sc.nextLine();
          }
  
          // interrupt the counter thread
          counter.interrupt();   
      }
  }//class Main