Re: NullPointerExceptions due to missing Spring constructor injection - Workaround
a) dont start a new thread for the same problem
b) you dont need this InjectorHolder.getInjector().inject(this); since
your repository is no longer abstract.
-igor
On Sat, Feb 28, 2009 at 11:29 AM, Christian Helmbold
wrote:
> I've found a workaround. Not elegant, but it works:
>
> public class ArticlePage extends WebPage
> {
> �...@springbean
> private ArticleRepository repository;
> private Article article;
>
> public ArticlePage()
> {
> InjectorHolder.getInjector().inject(this);
> construct(repository.findByName("index"));
> }
>
> private void construct(Article article)
> {
> add(new Label("name", new PropertyModel(article, "name")));
> //...
> }
>
> }
>
> It looks a bit better than service locator pattern but not much. Any other
> suggestions?
>
> Regards
> Christian
>
> --
> http://www.groovy-forum.de
>
>
>
> - Ursprüngliche Mail
>> Von: Christian Helmbold
>> An: users@wicket.apache.org
>> Gesendet: Samstag, den 28. Februar 2009, 20:14:02 Uhr
>> Betreff: AW: NullPointerExceptions due to missing Spring constructor
>> injection
>>
>> Hi Martjin,
>>
>> it is not possible to compile the code without static. Without static I get
>> the
>> compiler error: "cannot reference repository before supertype constructor has
>> been called". But I cannot write
>> public ArticlePage()
>> {
>> super();
>> this();
>> }
>> because each of them must be the first statement in the constructor. And I
>> cannot inject the reference directly into the constructor because of the
>> mentioned restriction of Wickets Spring integration (no constructor
>> injection).
>>
>> The only way out of this dilemma seems to be not to inject the repository.
>> But
>> if I cannot use injected reference within constructors I don't know why I
>> should
>> use Dependency Injection (DI). The constructors are very important in most
>> classes of Wicket applications. I could use the the service locator pattern
>> with
>> it's pros and cons. But I hope there is a solution with DI ...
>>
>> Regards
>> Christian
>>
>> --
>> http://www.groovy-forum.de
>>
>>
>>
>>
>>
>> -
>> To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org
>> For additional commands, e-mail: users-h...@wicket.apache.org
>
>
>
>
>
>
> -
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Re: NullPointerExceptions due to missing Spring constructor injection - Workaround
Christian Helmbold wrote:
I've found a workaround. Not elegant, but it works:
public class ArticlePage extends WebPage
{
@SpringBean
private ArticleRepository repository;
private Article article;
public ArticlePage()
{
InjectorHolder.getInjector().inject(this);
construct(repository.findByName("index"));
}
private void construct(Article article)
{
add(new Label("name", new PropertyModel(article, "name")));
//...
}
}
It looks a bit better than service locator pattern but not much. Any other
suggestions?
Create a abstract (or not) function on the base class and call it from
the base (now without arguments) constructor. Override this function to
return what you want based on "repository".
Adriano
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NullPointerExceptions due to missing Spring constructor injection - Workaround
I've found a workaround. Not elegant, but it works:
public class ArticlePage extends WebPage
{
@SpringBean
private ArticleRepository repository;
private Article article;
public ArticlePage()
{
InjectorHolder.getInjector().inject(this);
construct(repository.findByName("index"));
}
private void construct(Article article)
{
add(new Label("name", new PropertyModel(article, "name")));
//...
}
}
It looks a bit better than service locator pattern but not much. Any other
suggestions?
Regards
Christian
--
http://www.groovy-forum.de
- Ursprüngliche Mail
> Von: Christian Helmbold
> An: users@wicket.apache.org
> Gesendet: Samstag, den 28. Februar 2009, 20:14:02 Uhr
> Betreff: AW: NullPointerExceptions due to missing Spring constructor injection
>
> Hi Martjin,
>
> it is not possible to compile the code without static. Without static I get
> the
> compiler error: "cannot reference repository before supertype constructor has
> been called". But I cannot write
> public ArticlePage()
> {
>super();
>this();
> }
> because each of them must be the first statement in the constructor. And I
> cannot inject the reference directly into the constructor because of the
> mentioned restriction of Wickets Spring integration (no constructor
> injection).
>
> The only way out of this dilemma seems to be not to inject the repository.
> But
> if I cannot use injected reference within constructors I don't know why I
> should
> use Dependency Injection (DI). The constructors are very important in most
> classes of Wicket applications. I could use the the service locator pattern
> with
> it's pros and cons. But I hope there is a solution with DI ...
>
> Regards
> Christian
>
> --
> http://www.groovy-forum.de
>
>
>
>
>
> -
> To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org
> For additional commands, e-mail: users-h...@wicket.apache.org
-
To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org
For additional commands, e-mail: users-h...@wicket.apache.org
