Override jersey resource with guice

Question

I'm looking for a method to override jersey resources bounded with guice in GuiceServletContextListener. My code, which I'm trying to get working:

//Define Jersey resource interface
@Path("/books/{key}")
public interface BookDocument {

    public BookDAO getDao();

    public void setDao(BookDAO dao);
}

//Define default implementation
public class BookImpl implements Book {

    @Override
    public BookDAO getDao() {
        return dao;
    }

    @Inject
    @Override
    public void setDao(BookDAO dao) {
        this.dao = dao;
    }
}

//User wants to inject his implementation, so he define it
public class BookUserImpl implements Book {

    @Override
    public BookDAO getDao() {
        return dao;
    }

    @Inject
    @Override
    public void setDao(BookDAO dao) {
        this.dao = dao;
    }
}

//Inject default implementation of resource
public class ApplicationResourcesModule extends AbstractModule
{
    @Override
    protected void configure()
    {
        bind(Book).to(BookImpl);
    }
}

//But user wants to inject his implementation, so he bind it in users AbstractModule
public class ApplicationResourcesModuleUser extends AbstractModule
{
    @Override
    protected void configure()
    {
        bind(Book).to(BookUserImpl);
    }
}

//Bind all resources
public class JerseyGuiceConfig extends GuiceServletContextListener
{
    @Override
    protected Injector getInjector()
    {
        //Override default binding by user bindings.
        return Guice.createInjector(Modules.override(new ApplicationResourcesModule()).with(new ApplicationResourcesModuleUser()), new JerseyServletModule());
    }
}

But unfortunately this doesn't work, while I can't bind jersey resources in guice like interface to implementation, only bind(BookImpl.class) work's. But such binding is impossible to overwrite. If I try to override bind(BookImpl.class) with bind(BookUserImpl.class) I get an error Conflicting URI templates. The URI template /books/{key} for root resource class. while @Path should be unique. So is there any solution for my use case?

score 0 · Answer 1 · answered Aug 16 '13 at 08:00

i just wan't to warn you Modules.override does not work on Guice.createInjector(Stage.PRODUCTION,...) so you should use it carefully only for Development. You should create two context listeners and somehow (trough maven profiles lets say) setup the web.xml with proper implementation.

Better to use:

//Inject default implementation of resource
public class MainModule extends AbstractModule
{
    @Override
    protected void configure()
    {
        if(currentStage().equals(Stage.PRODUCTION) {
          install(new ApplicationResourcesModuleUser());
        } else {
          install(new ApplicationResourcesModule());
        }
    }
}

//Bind all resources
public class JerseyGuiceConfigPROD extends GuiceServletContextListener
{
    @Override
    protected Injector getInjector()
    {
        //Override default binding by user bindings.
        return Guice.createInjector(Stage.PRODUCTION, new MainModule(), new JerseyServletModule());
    }
}

public class JerseyGuiceConfigDEV extends GuiceServletContextListener
{
    @Override
    protected Injector getInjector()
    {
        //Override default binding by user bindings.
        return Guice.createInjector(Stage.DEVELOPMENT, new MainModule(), new JerseyServletModule());
    }
}

You can use @ImplementedBy annotation to your interface to say the default implementation should be. So, you don't have to bind it explicitly and you, if you bind it, it will override the annotation binding.

@Path("/books/{key}")
@ImplementedBy(BookImpl.class)
public interface Book {

    public BookDAO getDao();

    @Inject //it is enough to put the injection here, i think
    public void setDao(BookDAO dao);
}

I think this problem is not related to Book and Book implementations binding, but to a binding/registering of the servlets to the Jersey container. Could you paste whole stacktrace, the guice stacktraces are verbose and very helpful.

Override jersey resource with guice

1 Answers1