Groups > comp.lang.java.programmer > #37176

Re: Using main from abstract class in concrete class

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From	Andreas Leitgeb <avl@logic.at>
Newsgroups	comp.lang.java.programmer
Subject	Re: Using main from abstract class in concrete class
Date	Sun, 13 Aug 2017 11:38:18 -0000 (UTC)
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Andreas Leitgeb <avl@logic.at> wrote:
> Cecil Westerhof <Cecil@decebal.nl> wrote:
>> I have an abstract class. There can be several concrete classes that
>> extend this class. Is it possible to write a main in the abstract
>> class which will be used by the concrete classes and that in the main
>> a instance of the concrete class is created?
>
> The first part of the question is trivially yes: derived classes that
> don't provide their own main() will get your "abstract" class's main().
> I guess, you knew that already.
>
> For the other part,
> https://stackoverflow.com/questions/939932/how-to-determine-main-class-at-runtime-in-threaded-java-application
> seems to imply that short of some non-reliable environment variables
> or system properties there is no reliable way to know which class was
> originally started.

maybe a workaround:

Make your abstract class the real main class, and just pass it the name of
the requested subclass as first argument:

  java your.path.AbstractMain users.path.ConcreteSub ...

(and write the AbstractMain.main method accordingly)

Thread

Using main from abstract class in concrete class Cecil Westerhof <Cecil@decebal.nl> - 2017-08-13 11:47 +0200
  Re: Using main from abstract class in concrete class Andreas Leitgeb <avl@logic.at> - 2017-08-13 10:59 +0000
    Re: Using main from abstract class in concrete class Andreas Leitgeb <avl@logic.at> - 2017-08-13 11:38 +0000
  Re: Using main from abstract class in concrete class Cecil Westerhof <Cecil@decebal.nl> - 2017-08-13 15:43 +0200
  Re: Using main from abstract class in concrete class Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-08-13 10:32 -0400
    Re: Using main from abstract class in concrete class Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-08-13 10:37 -0400
    Re: Using main from abstract class in concrete class Cecil Westerhof <Cecil@decebal.nl> - 2017-08-13 17:17 +0200
      Re: Using main from abstract class in concrete class Andreas Leitgeb <avl@logic.at> - 2017-08-17 18:56 +0000
        Re: Using main from abstract class in concrete class Cecil Westerhof <Cecil@decebal.nl> - 2017-08-18 06:37 +0200
          Re: Using main from abstract class in concrete class Andreas Leitgeb <avl@logic.at> - 2017-08-18 19:48 +0000
            Re: Using main from abstract class in concrete class Cecil Westerhof <Cecil@decebal.nl> - 2017-08-18 23:37 +0200
              Re: Using main from abstract class in concrete class Cecil Westerhof <Cecil@decebal.nl> - 2017-08-19 01:32 +0200
  Re: Using main from abstract class in concrete class Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2017-08-13 12:03 -0500

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