Java Throwing Exceptions

Java Throwing Exceptions.

• We can throw our own exceptions on:
  1. either instances of Exception,
  2. one of its existing subclasses, or
  3. our own specialized exception classes
  Our own created exception example:

  ...
  class SecurityException extends Exception {
   SecurityException() { super(); }
   SecurityException( String desc ) {
              super( desc );
     }
  }
  ...
  public void checkRead( String s ) {
     if ( new File(s).isAbsolute(  ) || (s.indexOf("..") != -1) )
       throw new SecurityException("Access to file : "+ s +" denied.");
  }
  ...

• In this case, we throw in our method an SecurityException, which we earlier have created.