Guice注入通用类型

Question

我试图用Guice注入泛型类型.我有Repository <T>,它位于Cursor类中.

public class Cursor<T> {

    @Inject
    protected Repository<T> repository;

所以当我创建Cursor <User>时,我也希望Guice将我的存储库注入Repository <User>.有没有办法做到这一点？

Answer 1

你必须使用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);
  }
}

要获取实例Cursor<T>,Injector需要:

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);
  }
}

常见问题中的更多细节.