Re: Initializing Variables

From:

RedGrittyBrick <RedGrittyBrick@spamweary.invalid>

Newsgroups:

comp.lang.java.programmer

Date:

Thu, 27 May 2010 10:01:10 +0100

Message-ID:

<4bfe34d6$0$2540$da0feed9@news.zen.co.uk>

On 26/05/2010 23:28, Lew wrote:

Tom Anderson wrote:

Foo foo = new Foo();
try {
  foo.doProcessing();
}
catch (FooException ex) {
  doSomething(ex);
}
finally {
  foo.cleanup();
}

If new Foo() can also throw an exception, then wrap that whole lot in
a try-catch or whatever.

If the handling for FooExceptions from the constructor and the
processing is the same:

try {
  Foo foo = new Foo();
  try {
    foo.doProcessing();
  }
  finally {
    foo.cleanup();
  }
}
catch (FooException ex) [
  doSomething(ex);
}

Beautiful idioms.

A third, uglier but formally correct idiom is:

  final Foo resource;
  try
  {
    resource = new Foo();
  }
  catch ( FooException ex )
  {
    log( ex );
    return;
  }
  assert resource != null;
  try
  {
    resource.process();
  }
  catch ( FooException ex )
  {
    log( ex );
  }
  finally
  {
    resource.cleanup();
  }

I'm always a little uncomfortable when the exception handling overwhelms
and obscures the business logic:

new Foo().process().cleanup(); // <stimpy>Sigh!</stimpy>

The point of the exception handling mechanism is to separate error
handling code from business logic code. Sometimes it is hard to achieve
this.

--
RGB