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Groups > comp.lang.java.programmer > #30591
| From | Robert Klemme <shortcutter@googlemail.com> |
|---|---|
| Newsgroups | comp.lang.java.programmer |
| Subject | Re: a question about factory method |
| Date | 2014-12-19 01:39 +0100 |
| Message-ID | <cfhaduF4j02U1@mid.individual.net> (permalink) |
| References | (1 earlier) <m6usaq$6bg$1@dont-email.me> <ae5dcc85-b23a-4ee3-94b3-350e585f502d@googlegroups.com> <m6v1e2$u2d$1@dont-email.me> <74e17e36-3ccb-45c4-b50a-439d2799e3c7@googlegroups.com> <m6v9k5$5fb$1@dont-email.me> |
On 18.12.2014 20:24, Eric Sosman wrote:
> As to *how* a factory method might choose which of several classes
> to return, you already illustrated one way (paraphrased):
>
> public static Calendar getInstance(Date aDate, int choice) {
> if (choice == 1) {
> ... //return a GregorianCalendar object
> } else if (choice == 2) {
> ... //return a MayanCalendar object
> } else if (choice == 3) {
> ... //return a JulianCalendar object
> } else {
> return null;
> }
> }
>
> To me, this doesn't seem a huge advantage: The caller who writes
> `getInstance(date, 2)' could just as easily write `new MayanCalendar()'
> with about the same effect.
The crucial point is that the caller does not need to know the criteria
when to create what type. That _is_ a huge advantage.
Cheers
robert
--
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/
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a question about factory method John <xsli2@yahoo.com> - 2014-12-18 05:57 -0800
Re: a question about factory method Robert Klemme <shortcutter@googlemail.com> - 2014-12-18 15:28 +0100
Re: a question about factory method Silvio <silvio@internet.com> - 2014-12-18 15:43 +0100
Re: a question about factory method Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-12-18 10:37 -0500
Re: a question about factory method John <xsli2@yahoo.com> - 2014-12-18 08:04 -0800
Re: a question about factory method Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-12-18 12:04 -0500
Re: a question about factory method John <xsli2@yahoo.com> - 2014-12-18 10:43 -0800
Re: a question about factory method Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-12-18 14:24 -0500
Re: a question about factory method Robert Klemme <shortcutter@googlemail.com> - 2014-12-19 01:39 +0100
Re: a question about factory method Roedy Green <see_website@mindprod.com.invalid> - 2014-12-18 13:43 -0800
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