Re: Re: Re: Re: How to lock the access of methods within an action?
Sure...
On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote:
Hi Miguel,
thanks for the tip, is it possible to use this in a struts action which is
not thread save?
ciao 4 now
Julian
> Original-Nachricht
>Datum: Tue, 30 May 2006 09:28:36 -0300
>Von: Miguel Galves <[EMAIL PROTECTED]>
>An: Struts Users Mailing List
>Betreff: Re: Re: Re: How to lock the access of methods within an action?
>
> Julian,
>
> you can use the lock provided by Java 1.5 API...they are very simple to
> use.
> For istance, I use java.util.concurrent.Semaphore.
> The code above sho how to use it:
> private Semaphore sceneryLock = new Semaphore(1, true);
>
> public void removeScenery() throws Exception {
>
> try {
> sceneryLock.acquire();
>
> do your critical stuff here ...
> } catch (InterruptedException e) {
>
> } finally {
> sceneryLock.release();
> }
> }
>
> Hope it helps ...
>
> []s
>
> Miguel
>
> On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote:
> >
> > thx
> >
> > hmm, where can I find it, is it part of Spring?
> >
> > > Original-Nachricht --------
> > >Datum: Tue, 30 May 2006 18:36:06 +0800
> > >Von: Lixin Chu <[EMAIL PROTECTED]>
> > >An: Struts Users Mailing List
> > >Betreff: Re: Re: How to lock the access of methods within an action?
> > >
> i think transaction manager will take care of this.
> > >
> > > On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote:
> > > >
> > > > Thanks a lot for your answer!
> > > >
> > > > My thinking behind is the application level!
> > > >
> > > > I'm not sure but the goal is (my hope..)to solve
> > > >
> > > > this problem using aspect oriented programming or Spring
> > > >
> > > > although I'm not very aware of it.
> > > >
> > > > For example it would be nice to have one central configuration
there
> > you
> > > >
> > > > can say:
> > > >
> > > > this method -max-users 1-
> > > >
> > > > rule: throw error ….
> > > >
> > > > Should be done then a second users wants access to the method.
> > > >
> > > > Can you help me?
> > > >
> > > > Thanks a lot!
> > > >
> > > >> > Original-Nachricht
> > > > >Datum: Tue, 30 May 2006 10:55:17 +0200
> > > > >Von: The Jasper <[EMAIL PROTECTED]>
> > > > >An: Struts Users Mailing List
> > > > >Betreff: Re: How to lock the access of methods within an action?
> > > > >
> Hi,
> > > > >
> > > > > this sounds like a common database problem. You might want to
> > consider
> > > > > some kind of pessimistic locking. Basically you lock the object
> when
> > > > > you start editing and prevent all access to it for the duration
of
> > the
> > > > > lock. You could also do an optimistic lock which means that when
> you
> > > > > change an object it will only be committed if the object hasn't
> > > > > changed between the time you got your lock and the time you want
> to
> > > > > commit it. This doens't prevent you from having done unnecessary
> > work
> > > > > however. Most db's support optimistic locking, but not
pessimistic
> > > > > locking.
> > > > >
> > > > > If you want to use this at the application level you will have
to
> do
> > > > > it yourself. You could put a variable somewhere to track wether
an
> > > > > object is being edited and base access restrictions off of that.
> > > > > However you have to be very carefull about making sure you don't
> get
> > > > > any deadlock or race conditions.
> > > > >
> > > > > I suggest you delve into database world and read about how other
> > > > > people have solved this problem.
> > > > >
> > > > > mvg,
> > > > > Jasper
> > > > >
> > > > > On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote:
> > > > > > Hello everyone,
> > > > > >
> > > > > >>> Within our struts web application in which we have
> edit-actions
> > > > within
> > > > > a user
Re: Re: Re: Re: How to lock the access of methods within an action?
Hi Miguel,
thanks for the tip, is it possible to use this in a struts action which is not
thread save?
ciao 4 now
Julian
> Original-Nachricht
> Datum: Tue, 30 May 2006 09:28:36 -0300
> Von: Miguel Galves <[EMAIL PROTECTED]>
> An: Struts Users Mailing List
> Betreff: Re: Re: Re: How to lock the access of methods within an action?
>
> Julian,
>
> you can use the lock provided by Java 1.5 API...they are very simple to
> use.
> For istance, I use java.util.concurrent.Semaphore.
> The code above sho how to use it:
> private Semaphore sceneryLock = new Semaphore(1, true);
>
> public void removeScenery() throws Exception {
>
> try {
> sceneryLock.acquire();
>
> do your critical stuff here ...
> } catch (InterruptedException e) {
>
> } finally {
> sceneryLock.release();
> }
> }
>
> Hope it helps ...
>
> []s
>
> Miguel
>
> On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote:
> >
> > thx
> >
> > hmm, where can I find it, is it part of Spring?
> >
> > > Original-Nachricht --------
> > >Datum: Tue, 30 May 2006 18:36:06 +0800
> > >Von: Lixin Chu <[EMAIL PROTECTED]>
> > >An: Struts Users Mailing List
> > >Betreff: Re: Re: How to lock the access of methods within an action?
> > >
> i think transaction manager will take care of this.
> > >
> > > On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote:
> > > >
> > > > Thanks a lot for your answer!
> > > >
> > > > My thinking behind is the application level!
> > > >
> > > > I'm not sure but the goal is (my hope..)to solve
> > > >
> > > > this problem using aspect oriented programming or Spring
> > > >
> > > > although I'm not very aware of it.
> > > >
> > > > For example it would be nice to have one central configuration there
> > you
> > > >
> > > > can say:
> > > >
> > > > this method -max-users 1-
> > > >
> > > > rule: throw error ….
> > > >
> > > > Should be done then a second users wants access to the method.
> > > >
> > > > Can you help me?
> > > >
> > > > Thanks a lot!
> > > >
> > > >> > Original-Nachricht
> > > > >Datum: Tue, 30 May 2006 10:55:17 +0200
> > > > >Von: The Jasper <[EMAIL PROTECTED]>
> > > > >An: Struts Users Mailing List
> > > > >Betreff: Re: How to lock the access of methods within an action?
> > > > >
> Hi,
> > > > >
> > > > > this sounds like a common database problem. You might want to
> > consider
> > > > > some kind of pessimistic locking. Basically you lock the object
> when
> > > > > you start editing and prevent all access to it for the duration of
> > the
> > > > > lock. You could also do an optimistic lock which means that when
> you
> > > > > change an object it will only be committed if the object hasn't
> > > > > changed between the time you got your lock and the time you want
> to
> > > > > commit it. This doens't prevent you from having done unnecessary
> > work
> > > > > however. Most db's support optimistic locking, but not pessimistic
> > > > > locking.
> > > > >
> > > > > If you want to use this at the application level you will have to
> do
> > > > > it yourself. You could put a variable somewhere to track wether an
> > > > > object is being edited and base access restrictions off of that.
> > > > > However you have to be very carefull about making sure you don't
> get
> > > > > any deadlock or race conditions.
> > > > >
> > > > > I suggest you delve into database world and read about how other
> > > > > people have solved this problem.
> > > > >
> > > > > mvg,
> > > > > Jasper
> > > > >
> > > > > On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote:
> > > > > > Hello everyone,
> > > > > >
> > > > > >>> Within our struts web application in which we have
> edit-actions
> > > > within
> > > > > a user can be busy editing data in the form for several minu
Re: Re: Re: How to lock the access of methods within an action?
Julian,
you can use the lock provided by Java 1.5 API...they are very simple to use.
For istance, I use java.util.concurrent.Semaphore.
The code above sho how to use it:
private Semaphore sceneryLock = new Semaphore(1, true);
public void removeScenery() throws Exception {
try {
sceneryLock.acquire();
do your critical stuff here ...
} catch (InterruptedException e) {
} finally {
sceneryLock.release();
}
}
Hope it helps ...
[]s
Miguel
On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote:
thx
hmm, where can I find it, is it part of Spring?
> Original-Nachricht
>Datum: Tue, 30 May 2006 18:36:06 +0800
>Von: Lixin Chu <[EMAIL PROTECTED]>
>An: Struts Users Mailing List
>Betreff: Re: Re: How to lock the access of methods within an action?
>
> i think transaction manager will take care of this.
>
> On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote:
> >
> > Thanks a lot for your answer!
> >
> > My thinking behind is the application level!
> >
> > I'm not sure but the goal is (my hope..)to solve
> >
> > this problem using aspect oriented programming or Spring
> >
> > although I'm not very aware of it.
> >
> > For example it would be nice to have one central configuration there
you
> >
> > can say:
> >
> > this method -max-users 1-
> >
> > rule: throw error ….
> >
> > Should be done then a second users wants access to the method.
> >
> > Can you help me?
> >
> > Thanks a lot!
> >
> >> > Original-Nachricht
> > >Datum: Tue, 30 May 2006 10:55:17 +0200
> > >Von: The Jasper <[EMAIL PROTECTED]>
> > >An: Struts Users Mailing List
> > >Betreff: Re: How to lock the access of methods within an action?
> > >
> Hi,
> > >
> > > this sounds like a common database problem. You might want to
consider
> > > some kind of pessimistic locking. Basically you lock the object when
> > > you start editing and prevent all access to it for the duration of
the
> > > lock. You could also do an optimistic lock which means that when you
> > > change an object it will only be committed if the object hasn't
> > > changed between the time you got your lock and the time you want to
> > > commit it. This doens't prevent you from having done unnecessary
work
> > > however. Most db's support optimistic locking, but not pessimistic
> > > locking.
> > >
> > > If you want to use this at the application level you will have to do
> > > it yourself. You could put a variable somewhere to track wether an
> > > object is being edited and base access restrictions off of that.
> > > However you have to be very carefull about making sure you don't get
> > > any deadlock or race conditions.
> > >
> > > I suggest you delve into database world and read about how other
> > > people have solved this problem.
> > >
> > > mvg,
> > > Jasper
> > >
> > > On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote:
> > > > Hello everyone,
> > > >
> > > >>> Within our struts web application in which we have edit-actions
> > within
> > > a user can be busy editing data in the form for several minutes.
> > > >
> > > > The problem is, if another user is also editing the data at the
same
> > > time, one of the is eventually going to overwrite the changes of the
> > other and
> > > the other will have worked completely in vain. So my question would
be
> > > whether there's some way to prevent this from happening, some kind
of
> > "lock
> > > down" method for edit-actions? I think this problem is not uncommon,
> can
> > > someone give me a tip?
> > > >
> > > >>> thanks in advance
> > > > Julian
> > > >
> > > > --
> > > >
> > > >> Bis zu 70% Ihrer Onlinekosten sparen: GMX SmartSurfer!
> > > > Kostenlos downloaden: http://www.gmx.net/de/go/smartsurfer
> > > >
> > > >>
> -
> > > > To unsubscribe, e-mail: [EMAIL PROTECTED]
> > > > For additional commands, e-mail: [EMAIL PROTECTED]
> > > >
> > >
>-
> > > To unsubscribe, e-mail: [EMAIL PROTECTED]
> > > For additional commands, e-mail: [EMAIL PROTECTED]
> >
> > --
> >
> >> Bis zu 70% Ihrer Onlinekosten sparen: GMX SmartSurfer!
> > Kostenlos downloaden: http://www.gmx.net/de/go/smartsurfer
> >
> >> -
> > To unsubscribe, e-mail: [EMAIL PROTECTED]
> > For additional commands, e-mail: [EMAIL PROTECTED]
> >
> >
--
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Miguel Galves - Engenheiro de Computação
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"Não sabendo que era impossível, ele foi lá e fez..."
Re: Re: Re: How to lock the access of methods within an action?
thx hmm, where can I find it, is it part of Spring? > Original-Nachricht > Datum: Tue, 30 May 2006 18:36:06 +0800 > Von: Lixin Chu <[EMAIL PROTECTED]> > An: Struts Users Mailing List > Betreff: Re: Re: How to lock the access of methods within an action? > > i think transaction manager will take care of this. > > On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote: > > > > Thanks a lot for your answer! > > > > My thinking behind is the application level! > > > > I'm not sure but the goal is (my hope..)to solve > > > > this problem using aspect oriented programming or Spring > > > > although I'm not very aware of it. > > > > For example it would be nice to have one central configuration there you > > > > can say: > > > > this method -max-users 1- > > > > rule: throw error …. > > > > Should be done then a second users wants access to the method. > > > > Can you help me? > > > > Thanks a lot! > > > >> > Original-Nachricht > > >Datum: Tue, 30 May 2006 10:55:17 +0200 > > >Von: The Jasper <[EMAIL PROTECTED]> > > >An: Struts Users Mailing List > > >Betreff: Re: How to lock the access of methods within an action? > > > > Hi, > > > > > > this sounds like a common database problem. You might want to consider > > > some kind of pessimistic locking. Basically you lock the object when > > > you start editing and prevent all access to it for the duration of the > > > lock. You could also do an optimistic lock which means that when you > > > change an object it will only be committed if the object hasn't > > > changed between the time you got your lock and the time you want to > > > commit it. This doens't prevent you from having done unnecessary work > > > however. Most db's support optimistic locking, but not pessimistic > > > locking. > > > > > > If you want to use this at the application level you will have to do > > > it yourself. You could put a variable somewhere to track wether an > > > object is being edited and base access restrictions off of that. > > > However you have to be very carefull about making sure you don't get > > > any deadlock or race conditions. > > > > > > I suggest you delve into database world and read about how other > > > people have solved this problem. > > > > > > mvg, > > > Jasper > > > > > > On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote: > > > > Hello everyone, > > > > > > > >>> Within our struts web application in which we have edit-actions > > within > > > a user can be busy editing data in the form for several minutes. > > > > > > > > The problem is, if another user is also editing the data at the same > > > time, one of the is eventually going to overwrite the changes of the > > other and > > > the other will have worked completely in vain. So my question would be > > > whether there's some way to prevent this from happening, some kind of > > "lock > > > down" method for edit-actions? I think this problem is not uncommon, > can > > > someone give me a tip? > > > > > > > >>> thanks in advance > > > > Julian > > > > > > > > -- > > > > > > > >> Bis zu 70% Ihrer Onlinekosten sparen: GMX SmartSurfer! > > > > Kostenlos downloaden: http://www.gmx.net/de/go/smartsurfer > > > > > > > >> > - > > > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > >- > > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > -- > > > >> Bis zu 70% Ihrer Onlinekosten sparen: GMX SmartSurfer! > > Kostenlos downloaden: http://www.gmx.net/de/go/smartsurfer > > > >> - > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > -- Bis zu 70% Ihrer Onlinekosten sparen: GMX SmartSurfer! Kostenlos downloaden: http://www.gmx.net/de/go/smartsurfer - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Re: How to lock the access of methods within an action?
i think transaction manager will take care of this. On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote: Thanks a lot for your answer! My thinking behind is the application level! I'm not sure but the goal is (my hope..)to solve this problem using aspect oriented programming or Spring although I'm not very aware of it. For example it would be nice to have one central configuration there you can say: this method -max-users 1- rule: throw error …. Should be done then a second users wants access to the method. Can you help me? Thanks a lot! > Original-Nachricht >Datum: Tue, 30 May 2006 10:55:17 +0200 >Von: The Jasper <[EMAIL PROTECTED]> >An: Struts Users Mailing List >Betreff: Re: How to lock the access of methods within an action? > > Hi, > > this sounds like a common database problem. You might want to consider > some kind of pessimistic locking. Basically you lock the object when > you start editing and prevent all access to it for the duration of the > lock. You could also do an optimistic lock which means that when you > change an object it will only be committed if the object hasn't > changed between the time you got your lock and the time you want to > commit it. This doens't prevent you from having done unnecessary work > however. Most db's support optimistic locking, but not pessimistic > locking. > > If you want to use this at the application level you will have to do > it yourself. You could put a variable somewhere to track wether an > object is being edited and base access restrictions off of that. > However you have to be very carefull about making sure you don't get > any deadlock or race conditions. > > I suggest you delve into database world and read about how other > people have solved this problem. > > mvg, > Jasper > > On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote: > > Hello everyone, > > > >>> Within our struts web application in which we have edit-actions within > a user can be busy editing data in the form for several minutes. > > > > The problem is, if another user is also editing the data at the same > time, one of the is eventually going to overwrite the changes of the other and > the other will have worked completely in vain. So my question would be > whether there's some way to prevent this from happening, some kind of "lock > down" method for edit-actions? I think this problem is not uncommon, can > someone give me a tip? > > > >>> thanks in advance > > Julian > > > > -- > > > >> Bis zu 70% Ihrer Onlinekosten sparen: GMX SmartSurfer! > > Kostenlos downloaden: http://www.gmx.net/de/go/smartsurfer > > > >> - > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > >- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] -- Bis zu 70% Ihrer Onlinekosten sparen: GMX SmartSurfer! Kostenlos downloaden: http://www.gmx.net/de/go/smartsurfer - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Re: How to lock the access of methods within an action?
Thanks a lot for your answer! My thinking behind is the application level! I’m not sure but the goal is (my hope..)to solve this problem using aspect oriented programming or Spring although I’m not very aware of it. For example it would be nice to have one central configuration there you can say: this method -max-users 1- rule: throw error …. Should be done then a second users wants access to the method. Can you help me? Thanks a lot! > Original-Nachricht > Datum: Tue, 30 May 2006 10:55:17 +0200 > Von: The Jasper <[EMAIL PROTECTED]> > An: Struts Users Mailing List > Betreff: Re: How to lock the access of methods within an action? > > Hi, > > this sounds like a common database problem. You might want to consider > some kind of pessimistic locking. Basically you lock the object when > you start editing and prevent all access to it for the duration of the > lock. You could also do an optimistic lock which means that when you > change an object it will only be committed if the object hasn't > changed between the time you got your lock and the time you want to > commit it. This doens't prevent you from having done unnecessary work > however. Most db's support optimistic locking, but not pessimistic > locking. > > If you want to use this at the application level you will have to do > it yourself. You could put a variable somewhere to track wether an > object is being edited and base access restrictions off of that. > However you have to be very carefull about making sure you don't get > any deadlock or race conditions. > > I suggest you delve into database world and read about how other > people have solved this problem. > > mvg, > Jasper > > On 5/30/06, Julian Tillmann <[EMAIL PROTECTED]> wrote: > > Hello everyone, > > > >>> Within our struts web application in which we have edit-actions within > a user can be busy editing data in the form for several minutes. > > > > The problem is, if another user is also editing the data at the same > time, one of the is eventually going to overwrite the changes of the other and > the other will have worked completely in vain. So my question would be > whether there's some way to prevent this from happening, some kind of "lock > down" method for edit-actions? I think this problem is not uncommon, can > someone give me a tip? > > > >>> thanks in advance > > Julian > > > > -- > > > >> Bis zu 70% Ihrer Onlinekosten sparen: GMX SmartSurfer! > > Kostenlos downloaden: http://www.gmx.net/de/go/smartsurfer > > > >> - > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > >- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] -- Bis zu 70% Ihrer Onlinekosten sparen: GMX SmartSurfer! Kostenlos downloaden: http://www.gmx.net/de/go/smartsurfer - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
