HSQLDB: How to check if Server implementation is already running ? - JDBC JAVA

Hello, Dado!
You wrote on Sun, 20 Aug 2006 19:36:29 +0200:

D> I created application which start new Server() from a code and it use
D> only one database. But if I start another implementation of my
D> application (it is another main method) it is not neccessary to
D> create another Server but it is enough to add new database
D> (database.0 ... n). How to know that one Server is already running ?

Use Singleton pattern.


With best regards, Stepan Mozyra

Stepan Mozyra wrote:
> D> I created application which start new Server() from a code and it use
> D> only one database. But if I start another implementation of my
> D> application (it is another main method) it is not neccessary to
> D> create another Server but it is enough to add new database
> D> (database.0 ... n). How to know that one Server is already running ?
>
> Use Singleton pattern.

To me it sounds as if the original poster is starting
two programs (as in different JVM's).

Arne

"Arne Vajhoj" <arne@vajhoej.dk> je napisao u poruci interesnoj
grupi:fT6Gg.3850$_q4.2540@dukeread09...
> Stepan Mozyra wrote:
>> D> I created application which start new Server() from a code and it use
>> D> only one database. But if I start another implementation of my
>> D> application (it is another main method) it is not neccessary to
>> D> create another Server but it is enough to add new database
>> D> (database.0 ... n). How to know that one Server is already running ?
>>
>> Use Singleton pattern.
>
> To me it sounds as if the original poster is starting
> two programs (as in different JVM's).
>
> Arne

Yes of course, if you started application twice you got 2 different JVM. Is
something wierd with that ? Can I use Singelton once in 2 or more different
JVM-s ? I mean, I don't think that Singelton will know if some class
(Server for example) is instanced once in all JVM-s.

"Dado" <mario_zupan@inet.hr> je napisao u poruci interesnoj
grupi:ecbkcr$i2h$1@ss408.t-com.hr...
>
> "Arne Vajhoj" <arne@vajhoej.dk> je napisao u poruci interesnoj
> grupi:fT6Gg.3850$_q4.2540@dukeread09...
>> Stepan Mozyra wrote:
>>> D> I created application which start new Server() from a code and it
>>> use
>>> D> only one database. But if I start another implementation of my
>>> D> application (it is another main method) it is not neccessary to
>>> D> create another Server but it is enough to add new database
>>> D> (database.0 ... n). How to know that one Server is already running
>>> ?
>>>
>>> Use Singleton pattern.
>>
>> To me it sounds as if the original poster is starting
>> two programs (as in different JVM's).
>>
>> Arne
>
> Yes of course, if you started application twice you got 2 different JVM.
> Is something wierd with that ? Can I use Singelton once in 2 or more
> different JVM-s ? I mean, I don't think that Singelton will know if some
> class (Server for example) is instanced once in all JVM-s.
>
Maybe I need to use Singelton to allow only one instance of my application
and change my application to allow opening more than one database ?

Hello, Arne!
You wrote on Sun, 20 Aug 2006 20:12:02 -0400:

AV> To me it sounds as if the original poster is starting two programs
AV> (as in different JVM's).

Ok. I was wrong.
May be Server can opening some port, and any Application will communicate
with Server through it?


With best regards, Stepan Mozyra.

"Stepan Mozyra" <gorynych@voliacable.com> je napisao u poruci interesnoj
grupi:ecg066$1qst$1@behemoth.volia.net...
> Hello, Arne!
> You wrote on Sun, 20 Aug 2006 20:12:02 -0400:
>
> AV> To me it sounds as if the original poster is starting two programs
> AV> (as in different JVM's).
>
> Ok. I was wrong.
> May be Server can opening some port, and any Application will communicate
> with Server through it?
>
>
> With best regards, Stepan Mozyra.
>
Yes, but I didn't separate Server and client but start server when my app is
starts. Now I want to open more then one database (2 or more clients app).
IMO, I can avoid starting 2 server only if I have System.exit(0) when the
user try to starts second implementation of my app. But I was interesting to
finishing my app to work in a LAN. What is a practise from a HSQLDB point of
view?