public class CatchException
{
   public static void main(String[] args)
   {
       try
       {
          double area = areaOfCircle( -4 ); // May return an "error code"
       }
       catch (RuntimeException e)  // If "error code == RuntimeException)
       {
	  System.out.println("Error: " + e);
	  System.out.println("... continue...");
       }

       System.out.println("DONE");
   }

   public static double areaOfCircle( double radius )
   {
      if ( radius < 0 )
         throw new RuntimeException("***neg radius***"); 
                                            // Returns an exception code
      else
         return 3.1415 * radius * radius;
   }
}