I don't remember why I did this at that time. I will take a look at this when I
get some time and get back to you. FWIW, this is part of a yet to be completed
component-wise configuration system which I plan to get back to some time soon.
Hopefully, this is not a blocker for you as of now.
Thanks,
Hari
--
Hari Shreedharan
On Wednesday, September 19, 2012 at 11:02 PM, David Capwell wrote:
> I guess my real question would be why my custom ComponentConfiguration has to
> have this constructor. Here is quick sample of what i mean:
>
> public void createInstance() {
> final ComponentConfiguration config =
> ComponentConfigurationFactory.create(
> "name",
> RandomConfig.class.getName(),
> ComponentConfiguration.ComponentType.SOURCE);
> }
>
> public static class RandomConfig extends ComponentConfiguration {
>
> public RandomConfig() {
> super("my awesome name");
> }
> }
>
>
> This fails since the constructor doesn't exist. If i add a param "String
> ignored" then it works just fine.
> On Wed, Sep 19, 2012 at 10:47 PM, Hari Shreedharan <[email protected]
> (mailto:[email protected])> wrote:
> > From:
> > http://docs.oracle.com/javase/tutorial/reflect/member/ctorInstance.html
> > There are two reflective methods for creating instances of classes:
> > java.lang.reflect.Constructor.newInstance()
> > (http://docs.oracle.com/javase/7/docs/api/java/lang/reflect/Constructor.html#newInstance%28java.lang.Object...%29)
> > and Class.newInstance()
> > (http://docs.oracle.com/javase/7/docs/api/java/lang/Class.html#newInstance%28%29).
> > The former is preferred and is thus used in these examples because:
> > Class.newInstance()
> > (http://docs.oracle.com/javase/7/docs/api/java/lang/Class.html#newInstance%28%29)
> > can only invoke the zero-argument constructor, while
> > Constructor.newInstance()
> > (http://docs.oracle.com/javase/7/docs/api/java/lang/reflect/Constructor.html#newInstance%28java.lang.Object...%29)
> > may invoke any constructor, regardless of the number of parameters.
> > Class.newInstance()
> > (http://docs.oracle.com/javase/7/docs/api/java/lang/Class.html#newInstance%28%29)
> > throws any exception thrown by the constructor, regardless of whether it
> > is checked or unchecked. InvocationTargetException
> > (http://docs.oracle.com/javase/7/docs/api/java/lang/reflect/InvocationTargetException.html).
> > Class.newInstance()
> > (http://docs.oracle.com/javase/7/docs/api/java/lang/Class.html#newInstance%28%29)
> > requires that the constructor be visible; Constructor.newInstance()
> > (http://docs.oracle.com/javase/7/docs/api/java/lang/reflect/Constructor.html#newInstance%28java.lang.Object...%29)
> > may invoke private constructors under certain circumstances.
> >
> >
> >
> >
> > Thanks,
> > Hari
> >
> > --
> > Hari Shreedharan
> >
> >
> > On Wednesday, September 19, 2012 at 10:20 PM, David Capwell wrote:
> >
> > > I was going over the flume 1.2.0 code and i was wondering why
> > > the ComponentConfigurationFactory.create class has the following:
> > >
> > > confType = (Class<? extends ComponentConfiguration>) Class.forName(type);
> > > return confType.getConstructor(String.class).newInstance(type);
> > >
> > > Since type is the class, then why does the the class need a constructor
> > > that puts in the class name?
> > >
> > > thanks for your time reading this email.
> >
>
