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Groups > comp.lang.java.programmer > #21451

Re: single instance

Newsgroups comp.lang.java.programmer
Date 2013-01-16 14:51 -0800
References <iah6e8hb9ssp4q46ukh3scb81bjb9fdq1k@4ax.com>
Message-ID <a3f89eb0-abfb-4256-a81e-6d48cbca3830@googlegroups.com> (permalink)
Subject Re: single instance
From stledger@lanl.gov

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On Tuesday, January 1, 2013 1:23:45 PM UTC-7, Roedy Green wrote:
> What is the best way to ensure only a single instance of a Java program is running. I have used indicator files, but they can get screwed up if the user kills the program without going through the standard shutdown. Ideally, net new instance would just join the one already running. This is pure GUI, so I am not worried about adding new command line parms. -- Roedy Green Canadian Mind Products http://mindprod.com Students who hire or con others to do their homework are as foolish as couch potatoes who hire others to go to the gym for them.

I worked on a project with a requirement to run only one instance of our software at a time. We had a configuration file that had initialization values for the software. If the file was missing, then the code had default values. The code was running on one computer. Our code worked like this:

try{
Socket sock = new Socket();
sock.bind(new InetSocketAddress(int value read from configuration file or default value));
} catch (java.net.BindException)
{ tell user they are trying to start more than one instance and shutdown this copy after user acknowledges }

It's simple and seemed to always work. We only had to worry about a user double clicking the application. We did not worry about a batch file trying to start more than one instance.  Obviously, you could start one instance, delete the configuration file, then start the second instance.  We judged this to be a very unlikely possibility given our users, so we didn't worry about it. The software backed up its data on shutdown, and at regular intervals, and kept several backup files going back over the last week, so it was possible to restore the data to a given time over the past week of operation. YMMV.

John

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Thread

single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-01 12:23 -0800
  Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-01 16:40 -0500
    Re: single instance Robert Tomsick <robert+usenet@tomsick.net> - 2013-01-03 01:20 -0500
  Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-03 00:55 -0800
    Re: single instance Knute Johnson <nospam@knutejohnson.com> - 2013-01-03 19:31 -0800
      Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-03 19:49 -0800
      Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-03 19:56 -0800
        Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-04 12:18 -0500
          Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-04 10:22 -0800
            Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-04 13:44 -0500
              Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-04 11:03 -0800
                Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-04 14:12 -0500
              Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-05 21:56 -0500
                Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 19:22 -0500
                Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 20:23 -0500
                Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 20:43 -0500
                Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 20:47 -0500
                Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 20:51 -0500
                Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 20:24 -0500
                Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 20:46 -0500
                Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 20:58 -0500
                Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 21:08 -0500
                Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 21:19 -0500
                Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 21:31 -0500
                Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 21:41 -0500
                Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 22:00 -0500
                Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 22:11 -0500
                Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-07 00:23 -0500
                Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-02-24 18:20 -0500
                Re: single instance Joshua Cranmer <Pidgeot18@verizon.invalid> - 2013-01-06 21:39 -0600
                Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-07 00:30 -0500
                Re: single instance lipska the kat <lipskathekat@yahoo.co.uk> - 2013-01-07 08:53 +0000
                Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-02-24 18:18 -0500
                Re: single instance lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-02-25 08:31 +0000
                Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-02-24 18:17 -0500
                Re: single instance Lew <lewbloch@gmail.com> - 2013-01-06 17:32 -0800
                Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 20:47 -0500
                Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 20:53 -0500
                Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 21:01 -0500
          Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-05 21:59 -0500
            Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 19:34 -0500
              Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 20:00 -0500
  Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-03 07:12 -0800
    Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-03 09:56 -0800
      Re: single instance Martin Gregorie <martin@address-in-sig.invalid> - 2013-01-03 21:05 +0000
        Re: single instance Martin Gregorie <martin@address-in-sig.invalid> - 2013-01-03 22:08 +0000
        Re: single instance "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2013-01-05 12:48 +0000
          Re: single instance Martin Gregorie <martin@address-in-sig.invalid> - 2013-01-05 17:43 +0000
            Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-05 09:49 -0800
            Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-05 13:02 -0500
              Re: single instance Martin Gregorie <martin@address-in-sig.invalid> - 2013-01-05 20:29 +0000
                Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-05 19:07 -0800
                Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 20:04 -0500
            Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-05 21:40 -0500
    Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-05 22:10 -0500
      Re: single instance Knute Johnson <nospam@knutejohnson.com> - 2013-01-05 19:49 -0800
        Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-05 23:09 -0500
          Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 11:00 -0500
            Re: single instance Lew <lewbloch@gmail.com> - 2013-01-06 09:41 -0800
              Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 20:41 -0500
        Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-15 22:51 -0800
          Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-15 23:12 -0800
            Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-15 23:49 -0800
          Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-15 23:16 -0800
            Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-15 23:52 -0800
            Re: single instance Knute Johnson <nospam@knutejohnson.com> - 2013-01-16 08:46 -0800
              Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-16 10:46 -0800
                Re: single instance markspace <markspace@nospam.nospam> - 2013-01-16 13:01 -0800
                Re: single instance Knute Johnson <nospam@knutejohnson.com> - 2013-01-16 17:10 -0800
          Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-15 23:50 -0800
            Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-16 00:13 -0800
              Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-16 02:48 -0800
                Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-16 07:28 -0800
                Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-16 10:46 -0800
                Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-16 16:53 -0800
                Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-16 23:44 -0800
                Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-17 07:03 -0800
                Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-17 14:25 -0800
                Re: single instance Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2013-01-17 16:31 -0800
                Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-17 22:11 -0800
                Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-17 22:36 -0800
              Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-16 13:34 -0500
          Re: single instance Knute Johnson <nospam@knutejohnson.com> - 2013-01-16 08:45 -0800
          Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-16 13:29 -0500
            Re: single instance Knute Johnson <nospam@knutejohnson.com> - 2013-01-16 17:14 -0800
              Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-16 20:20 -0500
              Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-16 23:52 -0800
              Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-17 01:44 -0800
        Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-18 01:47 -0800
          Re: single instance Knute Johnson <nospam@knutejohnson.com> - 2013-01-18 20:50 -0800
            Re: single instance Roedy Green <see_website@mindprod.com.invalid> - 2013-01-20 00:53 -0800
              Re: single instance Lew <lewbloch@gmail.com> - 2013-01-20 12:00 -0800
                Re: single instance Knute Johnson <nospam@knutejohnson.com> - 2013-01-20 13:33 -0800
                Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-02-24 18:12 -0500
              Re: single instance Arne Vajhøj <arne@vajhoej.dk> - 2013-01-20 21:33 -0500
      Re: single instance "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2013-01-06 13:34 +0000
  Re: single instance Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-01-04 10:26 -0800
    Re: single instance Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-04 14:04 -0500
  Re: single instance stledger@lanl.gov - 2013-01-16 14:51 -0800
    Re: single instance stledger@lanl.gov - 2013-01-16 15:09 -0800

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