Re: Custom properties

From:

"visionset" <spam@ntlworld.com>

Newsgroups:

comp.lang.java.programmer

Date:

Thu, 03 May 2007 16:39:55 GMT

Message-ID:

<vfo_h.1268$o42.308@newsfe3-win.ntli.net>

"Thomas Fritsch" <i.dont.like.spam@invalid.com> wrote in message
news:newscache$wuxghj$d53$1@news.ops.de...

I would modify your requirement (interface CustomProperty) as follows:
(*) The class has to provide a public constructor taking a String
argument.
(*) The class does *not* have to provide a fromPropertyString(String)
   method. (hence you don't have to give up immutability)

Obviously the loading from a string gets more clumsy then.
But at least one can tuck away that clumsiness into a utility method:
public static Object createFromPropertyString(String s) {
   try {
     Constructor ctor = c.getDeclaredConstructor(new
Class[]{String.class};
     return ctor.newInstance(new Object[]{s});
   } catch(Exception e) {
     throw new RuntimeException(e);
   }
}

Thanks, that makes more sense.
I can also Generify it which I really wanted to do.

static <T> CompoundProperty

        createFromPropertyString(String propStr, Class<T> clazz) {

    try {

        Constructor ctor = clazz.getDeclaredConstructor(

        new Class[]{String.class});

        Object instance = ctor.newInstance(new Object[]{propStr});

        return (CompoundProperty)instance;

    } catch(Exception ex) {

        throw new RuntimeException(ex);

    }

}