SimpleScope help needd

[Richard Maher]

I have a service that takes a request scope object and a singleton. When I try to run the code below, I get the following error. How do I fix this?

Exception in thread "main" com.google.inject.ProvisionException: Guice provision errors:

1) Error in custom provider, com.google.inject.OutOfScopeException: Cannot access Key[type=com.google.analytics.frontend.feed.impl.gami.GuiceTester$FooImpl, annotation=[none]] outside of a scoping block

  at com.google.analytics.frontend.feed.impl.gami.GuiceTester$FooImpl.class(GuiceTester.java:30)

  while locating com.google.analytics.frontend.feed.impl.gami.GuiceTester$FooImpl

  while locating com.google.analytics.frontend.feed.impl.gami.GuiceTester$Foo

    for field at com.google.analytics.frontend.feed.impl.gami.GuiceTester$DataServiceProvider.foo(GuiceTester.java:1)

  while locating com.google.analytics.frontend.feed.impl.gami.GuiceTester$DataServiceProvider

    for field at com.google.analytics.frontend.feed.impl.gami.GuiceTester$ServiceImpl.unscopedDataServiceProvider(GuiceTester.java:79)

  while locating com.google.analytics.frontend.feed.impl.gami.GuiceTester$ServiceImpl

  while locating com.google.analytics.frontend.feed.impl.gami.GuiceTester$Service

1 error

at com.google.inject.internal.InjectorImpl$4.get(InjectorImpl.java:977)

at com.google.inject.internal.InjectorImpl.getInstance(InjectorImpl.java:1003)

at com.google.analytics.frontend.feed.impl.gami.GuiceTester.main(GuiceTester.java:133)

Caused by: com.google.inject.OutOfScopeException: Cannot access Key[type=com.google.analytics.frontend.feed.impl.gami.GuiceTester$FooImpl, annotation=[none]] outside of a scoping block

at com.google.common.inject.SimpleScope.getScopedObjectMap(SimpleScope.java:110)

at com.google.common.inject.SimpleScope.access$000(SimpleScope.java:48)

at com.google.common.inject.SimpleScope$2.get(SimpleScope.java:94)

at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:40)

at com.google.inject.internal.FactoryProxy.get(FactoryProxy.java:54)

at com.google.inject.internal.SingleFieldInjector.inject(SingleFieldInjector.java:53)

at com.google.inject.internal.MembersInjectorImpl.injectMembers(MembersInjectorImpl.java:110)

at com.google.inject.internal.ConstructorInjector.construct(ConstructorInjector.java:94)

at com.google.inject.internal.ConstructorBindingImpl$Factory.get(ConstructorBindingImpl.java:254)

at com.google.inject.internal.SingleFieldInjector.inject(SingleFieldInjector.java:53)

at com.google.inject.internal.MembersInjectorImpl.injectMembers(MembersInjectorImpl.java:110)

at com.google.inject.internal.ConstructorInjector.construct(ConstructorInjector.java:94)

at com.google.inject.internal.ConstructorBindingImpl$Factory.get(ConstructorBindingImpl.java:254)

at com.google.inject.internal.FactoryProxy.get(FactoryProxy.java:54)

at com.google.inject.internal.InjectorImpl$4$1.call(InjectorImpl.java:968)

at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1014)

at com.google.inject.internal.InjectorImpl$4.get(InjectorImpl.java:964)

... 2 more

// Code:

public class GuiceTester {

  public interface DataService {

  }

  public interface Foo {

  }

  @RequestScoped

  static class FooImpl implements Foo {

  }

  public interface Bar {

  }

  @Singleton

  static class BarImpl implements Bar {

  }

  static class DataServiceImpl implements DataService {

    private final Foo foo;

    private final Bar bar;

    @Inject

    DataServiceImpl(Foo foo, Bar bar) {

      this.foo = foo;

      this.bar = bar;

    }

    @Override

    public String toString() {

      return "MarsDataService [foo=" + foo + ", bar=" + bar + "]";

    }

  }

  public interface Service {

    Response process(Request request);

  }

  static class Request {

    private final Foo foo;

    Request(Foo foo) {

     this.foo = foo;

    }

    Foo getFoo() {

      return foo;

    }

  }

  static class Response {

  }

  static class ServiceImpl implements  Service {

    @Inject @Named("serviceScope") SimpleScope scope;

    @Inject DataServiceProvider unscopedDataServiceProvider;

    @Override

    public Response process(Request request) {

      scope.enter();

      try {

        // explicitly seed some seed objects...

        scope.seed(Key.get(Foo.class), request.getFoo());

        Provider<DataService> dataServiceProvider =

            scope.scope(Key.get(DataService.class), unscopedDataServiceProvider);

        DataService dataService = dataServiceProvider.get();

        System.out.println("DataService: " + dataService);

      } finally {

        scope.exit();

      }

      return null;

    }

  }

  static class DataServiceProvider implements Provider<DataService> {

    @Inject private Foo foo; // this is request scoped and seeded

    @Inject private Bar bar; // this is a singleton

    @Override

    public DataService get() {

      return new DataServiceImpl(foo, bar);

    }

  }

  public static void main(String[] args) {

    Injector injector =

        Guice.createInjector(Stage.DEVELOPMENT, new AbstractModule() {

          @Override

          protected void configure() {

            bind(Service.class).to(ServiceImpl.class);

            bind(Foo.class).to(FooImpl.class);

            bind(Bar.class).to(BarImpl.class);

            bind(DataServiceProvider.class);

            SimpleScope serviceScope = new SimpleScope();

            // tell Guice about the scope

            bindScope(RequestScoped.class, serviceScope);

            // make our scope instance injectable

            bind(SimpleScope.class)

                .annotatedWith(Names.named("serviceScope"))

                .toInstance(serviceScope);

          }

        });

    Service service = injector.getInstance(Service.class);

    Request request = new Request(new FooImpl());

    service.process(request);

  }

}

// End code

Thanks,

Richard

[Fred Faber]

Simple answer:

  * you bind Foo to FooImpl

  * FooImpl is bound in RequestScope

    - therefore, you can't inject FooImpl (or Foo) outside of Request Scope

  * you inject Foo into DataServiceProvider

  * you inject DataServiceProvider into ServiceImpl

  * you bind Service to ServiceImpl

  * you get an instance of Service outside of Scope

boom!

If you need an instance of Foo in DataServiceProvider, inject Provider<Foo>, and don't call get() until you're in scope.

And traverse upwards as need be...

-Fred

--
You received this message because you are subscribed to the Google Groups "google-guice" group.
To post to this group, send email to google...@googlegroups.com.
To unsubscribe from this group, send email to google-guice...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/google-guice?hl=en.