On Thu, Aug 21, 2008 at 7:40 PM, Andrei Ivanov <[EMAIL PROTECTED]> wrote:
> Hello,
> I'm having a difficult problem for which I hope someone here can help me..
> The short story: the parameters interceptor is unable to set a parameter.
> These are the classes involved:
>
> package model;
> public class Language extends org.apache.commons.lang.enums.Enum {
> protected Language(String name) {
> super(name);
> }
> }
>
> public interface IPreference {
> public <T extends model.Language> T getLanguage();
> }
>
> package project.model;
> public class Language extends model.Language {
> public static final Language ENGLISH = new Language("en");
> public static final Language RUSSIAN = new Language("ru");
> }
>
> public class Preference implements IPreference {
> public project.model.Language getLanguage() {
> return language;
> }
>
> public void setLanguage(project.model.Language language) {
> this.language = language;
> }
> }
>
> The choice of this hierarchy is to allow to have the first 2 classes
> in separate, generic and reusable bundle and the next 2 classes
> specific to a project.
>
> In the interface I'm using <T extends model.Language> T in the
> interface to avoid the need to cast the result of the method to a
> specific implementation and let the compiler use type inference to do
> it for me(and I think this is were the root of the problem is).
>
> I'm trying to use Preference inside an action and allow a user to
> choose the preferred language by sending a form parameter:
> preference.language
>
> The custom converter does it's job and converts 'en' to
> project.model.Language.ENGLISH
>
> The problem is that the parameters interceptor, through ognl, cannot
> find the setter for the type project.model.Language
> I've looked at the ognl sources and found that it is using
> introspection to find the properties of Preference.
> The introspector, trying to create a list of the properties, obtains a
> list of all methods of the class that respect the JavaBeans spec.
> The problem is that the compiler generates a second method inside Preference:
> public volatile model.Language getLanguage() {
> return getLanguage();
> }
> The introspector sees first the method written by me in the source and
> then the generated method, which overrides my method.
> After that, it find the setter, but the setter doesn't match the type
> returned by this second getter, so it ignores it.
> Now ognl will throw an exception saying it cannot set the value on a
> private field, because it doesn't find the setter.
> I've tried adding a second setter for the base Language class, and
> introspection finds it but now the converter isn't working because it
> cannot work with the base Language class.
>
> I've tried creating a PreferenceBeanInfo class, but it doesn't seem
> right to *manually* create a list of property descriptors that can get
> of of sync when Preference changes.
>
> Any ideas on how to resolve this problem?
> I know this is really an ognl problem, but ognl seems abandoned...
>
Just for the record, ognl 2.7.3-snapshot seems to work fine with this.
I hope the ognl devs will find the time to make a release.
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