[Pljava-dev] static variables

I've been starting to use pljava and find it very useful, but there's
something I want to know if it's possible. I want to have a static
variable that I can set and retrieve during a session. Something like
this:

public static String x;

public static String test() {
if (x==null) {
return "";
}
return x;
}

public static String testString(String me) {
x=me;
return me;
}

This is a trivial example, but what I want to do on the long run is to
setup a XML parser once (per session) and to avoid the overhead for
each calling of the function. Is it possible?

Thanks a lot,

Andres

I can't see any reason why you can't use static variables.

Just make sure that the variable is thread safe, as multiple threads
will be accessing it concurrently.

From looking at your code. Imagine 2 threads call your setter function,
then call the test() function. One of the threads will be using the
incorrect String (I guess?). So in this case using static variables
would probably produce unexpected results!

Andres Olarte wrote:
> I've been starting to use pljava and find it very useful, but there's
> something I want to know if it's possible. I want to have a static
> variable that I can set and retrieve during a session. Something like
> this:
>
> public static String x;
>
> public static String test() {
> if (x==null) {
> return "";
> }
> return x;
> }
>
> public static String testString(String me) {
> x=me;
> return me;
> }
>
> This is a trivial example, but what I want to do on the long run is to
> setup a XML parser once (per session) and to avoid the overhead for
> each calling of the function. Is it possible?
>
> Thanks a lot,
>
> Andres
> _______________________________________________
> Pljava-dev mailing list
> Pljava-dev at gborg.postgresql.org
> http://gborg.postgresql.org/mailman/listinfo/pljava-dev
>

Why thread safe? As far as I understand the architecture of pljava,
every connection has it's private JVM, therefore each tread (or
connection) will access each own variable. Since I don't want to
share the private static variable among connections, it should work.
Anybody has any experience with this?

On 3/12/07, Peter Henderson <peter.henderson at starjar.com> wrote:
> I can't see any reason why you can't use static variables.
>
> Just make sure that the variable is thread safe, as multiple threads
> will be accessing it concurrently.
>
> From looking at your code. Imagine 2 threads call your setter function,
> then call the test() function. One of the threads will be using the
> incorrect String (I guess?). So in this case using static variables
> would probably produce unexpected results!
>
>
> Andres Olarte wrote:
> > I've been starting to use pljava and find it very useful, but there's
> > something I want to know if it's possible. I want to have a static
> > variable that I can set and retrieve during a session. Something like
> > this:
> >
> > public static String x;
> >
> > public static String test() {
> > if (x==null) {
> > return "";
> > }
> > return x;
> > }
> >
> > public static String testString(String me) {
> > x=me;
> > return me;
> > }
> >
> > This is a trivial example, but what I want to do on the long run is to
> > setup a XML parser once (per session) and to avoid the overhead for
> > each calling of the function. Is it possible?
> >
> > Thanks a lot,
> >
> > Andres
> > _______________________________________________
> > Pljava-dev mailing list
> > Pljava-dev at gborg.postgresql.org
> > http://gborg.postgresql.org/mailman/listinfo/pljava-dev
> >
>
>
>