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I have a static method which has the following signature.

<code>
public static List createBeanCollection(){
}
</code>

I can't chage this, now this is the problem. how can i pass it
parameters
so in the method i can use them and return a dinamic list of objects,
i'm using ibatis
for test purposes i did the following.

<code>
public static List createBeanCollection(){
MiBean m = new MiBean();
m.setNombre("prueba");
List beans = new ArrayList();
beans.add(m);
return beans;

}
</code>

ok, it works fine, but now i want to replace the list i created by
hand with an
object that makes a query over a db, so the code would be this.
<code>
public static List createBeanCollection(){
List beans = miDao.onbtenObjetosPorId(valor);//dao that retrives
object from a db.
return beans;
}
</code>
but i cant use the "valor" parameter, due is not possible to use a no
static-variable
in a static method. at the moment i've resolved it in this way

<code>
public static int valor;//the variable was declared as static.

public static List createBeanCollection(){
List beans = miDao.onbtenObjetosPorId(valor);//i can use it now
return beans;
}
</code>
however this solution is not the best, because i'm expossing the
properties of my class
hope you can help me with this little problem, just remember i can't
change the method
signature.

Thank you in advance.

wrote:
> I have a static method which has the following signature.
>
> <code>
> public static List createBeanCollection(){
> }
> </code>
>
> I can't chage this, now this is the problem. how can i pass it
> parameters
> so in the method i can use them and return a dinamic list of objects,
> i'm using ibatis
> for test purposes i did the following.
>
> <code>
> public static List createBeanCollection(){
> MiBean m = new MiBean();
> m.setNombre("prueba");
> List beans = new ArrayList();
> beans.add(m);
> return beans;
>
> }
> </code>
>
> ok, it works fine, but now i want to replace the list i created by
> hand with an
> object that makes a query over a db, so the code would be this.
> <code>
> public static List createBeanCollection(){
> List beans = miDao.onbtenObjetosPorId(valor);//dao that retrives
> object from a db.
> return beans;
> }
> </code>
> but i cant use the "valor" parameter, due is not possible to use a no
> static-variable
> in a static method. at the moment i've resolved it in this way
>
> <code>
> public static int valor;//the variable was declared as static.
>
> public static List createBeanCollection(){
> List beans = miDao.onbtenObjetosPorId(valor);//i can use it now
> return beans;
> }
> </code>
> however this solution is not the best, because i'm expossing the
> properties of my class
> hope you can help me with this little problem, just remember i can't
> change the method
> signature.

You can make valor private and add a public setValor method.

But your basic problem is unsolvable. You can not an argument to
a method without adding an argument.

You have painted yourself into a corner with that requirement.

Arne

wrote:
> I have a static method which has the following signature.
>
> <code>
> public static List createBeanCollection(){
> }
> </code>
>
> I can't chage this, now this is the problem. how can i pass it
> parameters

May I ask why you cannot change the parameters? Is it to conform to some
interface or something similar?

> <code>
> public static int valor;//the variable was declared as static.
>
> public static List createBeanCollection(){
> List beans = miDao.onbtenObjetosPorId(valor);//i can use it now
> return beans;
> }
> </code>
> however this solution is not the best, because i'm expossing the
> properties of my class

I'm guessing that you would like something like this:

public class ProblemClass {
private static boolean validConfiguration = false;

private static int value;

public static void configureCollection(int value) {
ProblemClass.value = value;
validConfiguration = true;
}

public static List createBeanCollection() {
if (!validConfiguration)
throw new IllegalStateException("Trying to create a bean"+
" collection without a proper configuration!");
validConfiguration = false;
return miDao.onbtenObjetosPorId(value);
}
}

Disclaimers:
1. It would probably be better to use generics, unless this is pre-Java
5, in which case it would be better to upgrade to Java 6 and then use
generics.
2. I don't know Spanish, so I'm only guessing what your variable names
are talking about.
3. My code doesn't account for more complex fault-handling capabilities,
but that's alright for an example.

--
Beware of bugs in the above code; I have only proved it correct, not
tried it. -- Donald E. Knuth

wrote:
> I have a static method which has the following signature.
>
> <code>
> public static List createBeanCollection(){
> }
> </code>
>
> I can't chage this, now this is the problem. how can i pass it
> parameters
> so in the method i can use them and return a dinamic list of objects,
> i'm using ibatis
> for test purposes i did the following.
>
> <code>
> public static List createBeanCollection(){
> MiBean m = new MiBean();
> m.setNombre("prueba");
> List beans = new ArrayList();
> beans.add(m);
> return beans;
>
> }
> </code>
>
> ok, it works fine, but now i want to replace the list i created by
> hand with an
> object that makes a query over a db, so the code would be this.
> <code>
> public static List createBeanCollection(){
> List beans = miDao.onbtenObjetosPorId(valor);//dao that retrives
> object from a db.
> return beans;
> }
> </code>
> but i cant use the "valor" parameter, due is not possible to use a no
> static-variable
> in a static method. at the moment i've resolved it in this way
>
> <code>
> public static int valor;//the variable was declared as static.
>
> public static List createBeanCollection(){
> List beans = miDao.onbtenObjetosPorId(valor);//i can use it now
> return beans;
> }
> </code>
> however this solution is not the best, because i'm expossing the
> properties of my class
> hope you can help me with this little problem, just remember i can't
> change the method
> signature.
>
> Thank you in advance.

Probably a better way to handle this is just to use a setter to set the
value of valor.

public class BeanWrapper {

private int valor;

public static void setValor( int v )
{
valor = v;
}

public static List createBeanCollection()
{
return miDao.onbtenObjectosPorId( valor );
}
}

Now this is a tad dangerous, you'll get issues with concurrency and
what-not. But it might suit your needs.

Have you considered a non-static method? It seems to me that would solve
a lot more problems. You could also inject a non-static object into the
wrapper class.

public class BeanWrapper {

private Beans b;

public static void setValor( Beans v )
{
b = v;
}

public static List createBeanCollection()
{
return b.onbtenObjectosPorId();
}
}

where a Beans object has the "valor" injected into it, ie.,

setValor( new Beans( 1 ) );

Now you also have a fully constructed object that you can synchronize
on, for example. And it's private, so no one else can call it but your
createBeanCollection() method.

On 3 mayo, 15:12, Joshua Cranmer <Pidgeo...@verizon.invalid> wrote:
> ojv...@gmail.com wrote:
> > I have a static method which has the following signature.
>
> > <code>
> > public static List createBeanCollection(){
> > }
> > </code>
>
> > I can't chage this, now this is the problem. how can i pass it
> > parameters
>
> May I ask why you cannot change the parameters? Is it to conform to some
> interface or something similar?
>
> > <code>
> > public static int valor;//the variable was declared as static.
>
> > public static List createBeanCollection(){
> > List beans = miDao.onbtenObjetosPorId(valor);//i can use it now
> > return beans;
> > }
> > </code>
> > however this solution is not the best, because i'm expossing the
> > properties of my class
>
> I'm guessing that you would like something like this:
>
> public class ProblemClass {
> private static boolean validConfiguration = false;
>
> private static int value;
>
> public static void configureCollection(int value) {
> ProblemClass.value = value;
> validConfiguration = true;
> }
>
> public static List createBeanCollection() {
> if (!validConfiguration)
> throw new IllegalStateException("Trying to create a bean"+
> " collection without a proper configuration!");
> validConfiguration = false;
> return miDao.onbtenObjetosPorId(value);
> }
>
> }
>
> Disclaimers:
> 1. It would probably be better to use generics, unless this is pre-Java
> 5, in which case it would be better to upgrade to Java 6 and then use
> generics.
> 2. I don't know Spanish, so I'm only guessing what your variable names
> are talking about.
> 3. My code doesn't account for more complex fault-handling capabilities,
> but that's alright for an example.
>
> --
> Beware of bugs in the above code; I have only proved it correct, not
> tried it. -- Donald E. Knuth

thank you for answer so soon. ok i think your solution is better than
the one i'm using now. about the use of generics mmm. i'll check it
because this is a List for ireport reporter so i don't know if it is
supported. the variable name doesn't matter, it doesn't have any
meaning. it seems to work so i'll give it a try.

On 3 mayo, 15:11, Arne Vajhøj <a...@vajhoej.dk> wrote:
> ojv...@gmail.com wrote:
> > I have a static method which has the following signature.
>
> > <code>
> > public static List createBeanCollection(){
> > }
> > </code>
>
> > I can't chage this, now this is the problem. how can i pass it
> > parameters
> > so in the method i can use them and return a dinamic list of objects,
> > i'm using ibatis
> > for test purposes i did the following.
>
> > <code>
> > public static List createBeanCollection(){
> > MiBean m = new MiBean();
> > m.setNombre("prueba");
> > List beans = new ArrayList();
> > beans.add(m);
> > return beans;
>
> > }
> > </code>
>
> > ok, it works fine, but now i want to replace the list i created by
> > hand with an
> > object that makes a query over a db, so the code would be this.
> > <code>
> > public static List createBeanCollection(){
> > List beans = miDao.onbtenObjetosPorId(valor);//dao that retrives
> > object from a db.
> > return beans;
> > }
> > </code>
> > but i cant use the "valor" parameter, due is not possible to use a no
> > static-variable
> > in a static method. at the moment i've resolved it in this way
>
> > <code>
> > public static int valor;//the variable was declared as static.
>
> > public static List createBeanCollection(){
> > List beans = miDao.onbtenObjetosPorId(valor);//i can use it now
> > return beans;
> > }
> > </code>
> > however this solution is not the best, because i'm expossing the
> > properties of my class
> > hope you can help me with this little problem, just remember i can't
> > change the method
> > signature.
>
> You can make valor private and add a public setValor method.
>
> But your basic problem is unsolvable. You can not an argument to
> a method without adding an argument.
>
> You have painted yourself into a corner with that requirement.
>
> Arne

yes i know that it's not the best way to get something from some
method. the point is that this is a requirement of ireport in order to
populate it with a list of objects instead of using an sql data
source. so that the reazon than i can change the signature.

>
> Probably a better way to handle this is just to use a setter to set the
> value of valor.
>
> public class BeanWrapper {
>
> private int valor;
>
> public static void setValor( int v )
> {
> valor = v;
> }
>
> public static List createBeanCollection()
> {
> return miDao.onbtenObjectosPorId( valor );
> }
>
> }

but with this code you will get an "non-static variable valor cannot
be referenced from a static context" so this wont work.

> Now this is a tad dangerous, you'll get issues with concurrency and
> what-not. But it might suit your needs.


yes in fact i was thinking in sincronized code in the method that
calls this class.

>
> Have you considered a non-static method? It seems to me that would solve
> a lot more problems. You could also inject a non-static object into the
> wrapper class.

the problem is that this is the signature a must use. i cant rewrite
it to "public List mimethod()" this is an ibatis requirementin order
to populate a report whit objects instead of using an sql data source.
>
> public class BeanWrapper {
>
> private Beans b;
>
> public static void setValor( Beans v )
> {
> b = v;
> }
>
> public static List createBeanCollection()
> {
> return b.onbtenObjectosPorId();
> }
>
> }


yes it souns fine. but the problem is the same i mentioned above.
>
> where a Beans object has the "valor" injected into it, ie.,
>
> setValor( new Beans( 1 ) );
>
> Now you also have a fully constructed object that you can synchronize
> on, for example. And it's private, so no one else can call it but your
> createBeanCollection() method.

thank you for your time.

wrote:
>> Probably a better way to handle this is just to use a setter to set the
>> value of valor.
>>
>> public class BeanWrapper {
>>
>> private int valor;
>>
>> public static void setValor( int v )
>> {
>> valor = v;
>> }
>>
>> public static List createBeanCollection()
>> {
>> return miDao.onbtenObjectosPorId( valor );
>> }
>>
>> }
>
> but with this code you will get an "non-static variable valor cannot
> be referenced from a static context" so this wont work.


Oops, both examples should have "static" as part of the variable
declaration. That's what I get for not compiling the code.

wrote:
> I have a static method which has the following signature.
>
> <code>
> public static List createBeanCollection(){
> }
> </code>
>
> I can't chage this, now this is the problem. how can i pass it
> parameters
> so in the method i can use them and return a dinamic list of objects,
> i'm using ibatis
> for test purposes i did the following.
>
> <code>
> public static List createBeanCollection(){
> MiBean m = new MiBean();
> m.setNombre("prueba");
> List beans = new ArrayList();
> beans.add(m);
> return beans;
>
> }
> </code>
>
> ok, it works fine, but now i want to replace the list i created by
> hand with an
> object that makes a query over a db, so the code would be this.
> <code>
> public static List createBeanCollection(){
> List beans = miDao.onbtenObjetosPorId(valor);//dao that retrives
> object from a db.
> return beans;
> }
> </code>
> but i cant use the "valor" parameter, due is not possible to use a no
> static-variable
> in a static method. at the moment i've resolved it in this way
>
> <code>
> public static int valor;//the variable was declared as static.
>
> public static List createBeanCollection(){
> List beans = miDao.onbtenObjetosPorId(valor);//i can use it now
> return beans;
> }
> </code>
> however this solution is not the best, because i'm expossing the
> properties of my class
> hope you can help me with this little problem, just remember i can't
> change the method
> signature.
>
> Thank you in advance.

If you need to pass something in, you should make sure its thread safe.
One way to do that is have a ThreadLocal with your parameters.

--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/>

Daniel Pitts wrote:

> If you need to pass something in, you should make sure its thread safe.
> One way to do that is have a ThreadLocal with your parameters.
>

Assuming, of course, that "valor" isn't supposed to be a global shared
variable.

But yes, going from a local variable to a global one creates all sorts
of problems if you don't understand what a static field does. Good
catch there.