Guice injecting Generic type

Question

I'am trying to Inject generic type with Guice. I have Repository< T > which is located in the Cursor class.

public class Cursor<T> {      @Inject     protected Repository<T> repository; 

So when I create Cursor< User >, I also want the Guice to inject my repository to Repository< User >. Is there a way to do this?

Answer 1

You have to use a TypeLiteral:

import com.google.inject.AbstractModule; import com.google.inject.TypeLiteral;  public class MyModule extends AbstractModule {    @Override   protected void configure() {     bind(new TypeLiteral<Repository<User>>() {}).to(UserRepository.class);   } } 

To get an instance of Cursor<T>, an Injector is required:

import com.google.inject.Guice; import com.google.inject.Injector; import com.google.inject.Key; import com.google.inject.TypeLiteral;  public class Main {    public static void main(String[] args) {     Injector injector = Guice.createInjector(new MyModule());     Cursor<User> instance =          injector.getInstance(Key.get(new TypeLiteral<Cursor<User>>() {}));     System.err.println(instance.repository);   } } 

More details in the FAQ.