RE: `Single Proxy for a Whole Collection` problem
Hello, > -Original Message- > From: Andrei Ivanov [mailto:[EMAIL PROTECTED] > I see here > http://java.sun.com/j2se/1.4.2/docs/api/java/util/Vector.html > that Vector implements the List interface, and I used Vector because it's that means that you can assign a Vector to a field of type List, but not vice versa. > in the ojb documentation: > "The association is implemented by the Vector attribute allArticlesInGroup > on the ProductGroup class." > http://db.apache.org/ojb/tutorial3.html#Using%20a%20Single%20Proxy%20for%20a %20Whole%20Collection In that example, no proxies are used for that collection. If I had written these classes, I would have used interface types in the declarations and ArrayList for the instantiation. There is a performance advantage of ArrayList against Vector, because access to elements is synchronized in Vector. To sum up: Vector is evil. Olli -- Oliver Matz ppi Media GmbH Deliusstraße 10 D-24114 Kiel phone +49 (0) 43 1-53 53-422 fax +49 (0) 43 1-53 53-2 22 email mailto:[EMAIL PROTECTED] web www.ppi.de Explore your printnet! DRUPA 2004 Düsseldorf, Germany, 6 - 19 May 2004, Booth 6E62 - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: `Single Proxy for a Whole Collection` problem
On Thu, 8 Jan 2004 [EMAIL PROTECTED] wrote:
> Hello,
>
> > public class ProductTO implements java.io.Serializable {
> >
> > protected int id;
> > protected String name;
> > protected Vector symbols;
>
> 'Vector' is not a good idea. You should use an interface
> type such as Collection or List for the type declaration ...
>
> > getters and setters...
>
> ... and also for the parameter and return types.
>
> > My problem is that I get an exception when I mark it as a proxy:
> >
> > [PersistentField] ERROR: while set field:
> > object class[ com.ines.flanco.model.ProductTO
> > target field: symbols
> > target field type: class java.util.Vector
> > object value class: org.apache.ojb.broker.accesslayer.ListProxy
>
> This is a good error message, isn't it?
> The proxy is of type ListProxy, which implements the List interface
> but is not assignable to a field of type Vector.
Indeed, it seemd to work, thanks.
I see here http://java.sun.com/j2se/1.4.2/docs/api/java/util/Vector.html
that Vector implements the List interface, and I used Vector because it's
in the ojb documentation:
"The association is implemented by the Vector attribute allArticlesInGroup
on the ProductGroup class."
http://db.apache.org/ojb/tutorial3.html#Using%20a%20Single%20Proxy%20for%20a%20Whole%20Collection
>
>
> HTH,
> Olli
> --
> Oliver Matz
> ppi Media GmbH
> Deliusstraße 10
> D-24114 Kiel
> phone +49 (0) 43 1-53 53-422
> fax +49 (0) 43 1-53 53-2 22
> email mailto:[EMAIL PROTECTED]
> web www.ppi.de
>
> Explore your printnet!
>
> DRUPA 2004
> Düsseldorf, Germany, 6 - 19 May 2004, Booth 6E62
>
>
> -
> To unsubscribe, e-mail: [EMAIL PROTECTED]
> For additional commands, e-mail: [EMAIL PROTECTED]
>
>
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To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
RE: `Single Proxy for a Whole Collection` problem
Hello,
> public class ProductTO implements java.io.Serializable {
>
> protected int id;
> protected String name;
> protected Vector symbols;
'Vector' is not a good idea. You should use an interface
type such as Collection or List for the type declaration ...
> getters and setters...
... and also for the parameter and return types.
> My problem is that I get an exception when I mark it as a proxy:
>
> [PersistentField] ERROR: while set field:
> object class[ com.ines.flanco.model.ProductTO
> target field: symbols
> target field type: class java.util.Vector
> object value class: org.apache.ojb.broker.accesslayer.ListProxy
This is a good error message, isn't it?
The proxy is of type ListProxy, which implements the List interface
but is not assignable to a field of type Vector.
HTH,
Olli
--
Oliver Matz
ppi Media GmbH
Deliusstraße 10
D-24114 Kiel
phone +49 (0) 43 1-53 53-422
fax +49 (0) 43 1-53 53-2 22
email mailto:[EMAIL PROTECTED]
web www.ppi.de
Explore your printnet!
DRUPA 2004
Düsseldorf, Germany, 6 - 19 May 2004, Booth 6E62
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
