如何使用Guice注入Google App Engine数据存储区？

Question

I'm trying to inject Google App Engine's datastore via Guice into my service:

public class FooServiceImpl implements FooService {

    private final DatastoreService datastoreService;

    @Inject
    public FooServiceImpl (DatastoreService datastoreService) {
        this.datastoreService = datastoreService;
    }
}

But when I try to run it, I get the following error:

No implementation for com.google.appengine.api.datastore.DatastoreService was bound.

Answer 1

Add @Provides method to your module:

@Provides
DatastoreService provideDatastoreService(){
    return DatastoreServiceFactory.getDatastoreService();
}