针对Android HILT SingletonComponent的设计模式，可以采用以下示例的方式实现：

@Singleton
@Component
public interface AppComponent {
   // ...
}

@Module
@InstallIn(ApplicationComponent.class)
public class AppModule {
   @Singleton
   @Provides
   public SomeSingletonObj provideSomeSingletonObj() {
       return new SomeSingletonObj();
   }
}

public class SomeSingletonObj {
   // ...
}

而对于GoF Singleton instance设计模式的实现，可以采用以下示例的方式实现：

public class Singleton {
   private static Singleton instance;
   private Singleton() {
      // private constructor
   }
   public static Singleton getInstance() {
      if (instance == null) {
         instance = new Singleton();
      }
      return instance;
   }  
}