Constructor throwing exception

[Emmanuel Lécharny <el...@symas.com>]

Hi,

yesterday, we had a quick chat with Radovan about the fact that some
constructors are throwing an Exception, like the DefaultSchemaManager().

Actually, all of the 4 DefaultSchemaManager throw an Exception, but we
can easily get rid of the 'throw' for 3 of them. The question is what
should we do with the default constructor ? The thrown Exception is the
one thrown when we intialise it :

    public DefaultSchemaManager() throws Exception
    {
        ...
        loadAllEnabled();  <---- This is throwing an Exception
    }

It makes little sense to thrown an exception in this case : the default
schema is not going to be altered in this very case (the default
constructor) because it's part of the API as a Jar file we provide. If
this jar file is incorrect, then the full API is incorrect.

I would suggest we stop throwing an Exception, and catch the one thrown
by loadAllEnabled() in the constructor, logging some message (which will
never happend anyway).

There is also a second change I'd like to do : everywhere we throw an
Exception in the API, we should at least throw a LdapException instead.

wdyt ?

Re: Constructor throwing exception

[Emmanuel Lécharny <el...@gmail.com>]

Le 18/02/16 13:29, Lucas Theisen a écrit :
> For the first situation, I would convert it to a runtime exception, perhaps
> ProviderException (even though we are not an spi provider), or
> IllegalStateException, or even an Error, like AssertionError as this really
> is a precondition we are asserting.  This is an irrecoverable condition of
> the application itself, nothing the user could do about it.  That way if we
> break something we could get a useful error...

Plainly agree. This is what we already to for some of the SchemaLoader
constructor.

Re: Constructor throwing exception

[Lucas Theisen <lu...@pastdev.com>]

For the first situation, I would convert it to a runtime exception, perhaps
ProviderException (even though we are not an spi provider), or
IllegalStateException, or even an Error, like AssertionError as this really
is a precondition we are asserting.  This is an irrecoverable condition of
the application itself, nothing the user could do about it.  That way if we
break something we could get a useful error...
On Feb 18, 2016 1:27 AM, "Emmanuel Lécharny" <el...@gmail.com> wrote:

> Le 18/02/16 06:49, Emmanuel Lécharny a écrit :
> > Hi,
> >
> > yesterday, we had a quick chat with Radovan about the fact that some
> > constructors are throwing an Exception, like the DefaultSchemaManager().
> >
> > Actually, all of the 4 DefaultSchemaManager throw an Exception, but we
> > can easily get rid of the 'throw' for 3 of them. The question is what
> > should we do with the default constructor ? The thrown Exception is the
> > one thrown when we intialise it :
> >
> >     public DefaultSchemaManager() throws Exception
> >     {
> >         ...
> >         loadAllEnabled();  <---- This is throwing an Exception
> >     }
> >
> > It makes little sense to thrown an exception in this case : the default
> > schema is not going to be altered in this very case (the default
> > constructor) because it's part of the API as a Jar file we provide. If
> > this jar file is incorrect, then the full API is incorrect.
> >
> > I would suggest we stop throwing an Exception, and catch the one thrown
> > by loadAllEnabled() in the constructor, logging some message (which will
> > never happend anyway).
> >
> > There is also a second change I'd like to do : everywhere we throw an
> > Exception in the API, we should at least throw a LdapException instead.
> >
> > wdyt ?
> Note that the problem also hits the SchemaLoader classes. Although it's
> harder to get rid of the constructor's exceptions in this case, we can
> at least make the methods and constructors throw meaningfull exceptions,
> like LdapException and IOException instead of the generic Exception...
>

Re: Constructor throwing exception

[Emmanuel Lécharny <el...@gmail.com>]

Le 18/02/16 06:49, Emmanuel Lécharny a écrit :
> Hi,
>
> yesterday, we had a quick chat with Radovan about the fact that some
> constructors are throwing an Exception, like the DefaultSchemaManager().
>
> Actually, all of the 4 DefaultSchemaManager throw an Exception, but we
> can easily get rid of the 'throw' for 3 of them. The question is what
> should we do with the default constructor ? The thrown Exception is the
> one thrown when we intialise it :
>
>     public DefaultSchemaManager() throws Exception
>     {
>         ...
>         loadAllEnabled();  <---- This is throwing an Exception
>     }
>
> It makes little sense to thrown an exception in this case : the default
> schema is not going to be altered in this very case (the default
> constructor) because it's part of the API as a Jar file we provide. If
> this jar file is incorrect, then the full API is incorrect.
>
> I would suggest we stop throwing an Exception, and catch the one thrown
> by loadAllEnabled() in the constructor, logging some message (which will
> never happend anyway).
>
> There is also a second change I'd like to do : everywhere we throw an
> Exception in the API, we should at least throw a LdapException instead.
>
> wdyt ?
Note that the problem also hits the SchemaLoader classes. Although it's
harder to get rid of the constructor's exceptions in this case, we can
at least make the methods and constructors throw meaningfull exceptions,
like LdapException and IOException instead of the generic Exception...