package exception;

public class Examples {

  public class MyException extends Exception {

    public MyException (String message) {
      super (message);
    }
    
  }

  private Object object;

  /** Constructs Examples. */
  public Examples () {
    try {
//      trial ();
//      handlesException ();
//      passesOnException ();
//      handelsAndThrowsException ();
      handelsAndThrowsMyException ();
      System.err.println ("the end");
   } catch (Exception error) {
      System.err.println ("some error occured in Examples");
      error.printStackTrace ();
    } catch (Error error) {} //never ignore Exceptions or Errors!
  }

  private void handelsAndThrowsMyException () throws MyException {
    try {
      int i = 10 / 0;
    } catch (ArithmeticException error) {
      System.err.println ("handelsAndThrowsMyException: handled division by zero");
      throw new MyException ("This was an intentional division by zero");
    }
  }

  private void handelsAndThrowsException () {
    try {
      int i = 10 / 0;
    } catch (ArithmeticException error) {
      System.err.println ("handelsAndThrowsException: handled division by zero");
      throw error;
    }
  }

  private void passesOnException () throws ArithmeticException{
    int i = 10 / 0;
    System.err.println ("passesOnException");
  }

  private void handlesException () {
    try {
      int i = 10 / 0;
    } catch (ArithmeticException error) {
      System.err.println ("handlesException: handled division by zero");
    }
  }

  private void trial () throws MyException {
    try {
//      System.err.println (object.toString ());
//      int i = 10 / 0;
//      String text = "12345".substring (10);
//      System.out.println ("int number=" + Integer.parseInt ("5.0"));
      char ch = "12345".charAt (5);
      System.out.println ("ch = '" + ch + "'");
//      throw new MyException ("dummy one!");
      System.err.println ("this code is executed only if no exception is thrown");
    } catch (NullPointerException error) {
      System.err.println ("object is null");
      System.err.println ("message = " + error.getMessage ());
      error.printStackTrace ();
    } catch (ArithmeticException error) {
      System.err.println ("division by zero");
      error.printStackTrace ();
    }
  }
  
  

  public static void main (String [] args) {
    new Examples ();
  }
}