Can I have a Guice abstract module with a constructor & local instance to provide a dynamic binding?

Question

Can I have a Guice abstract module with a constructor & local instance to provide a dynamic binding? Can a Guice module have a constructor?

I understand that using providers/factory builder are better way, but in my case, I would end up creating n-providers or factory builder with concrete logic (nearly a hundred) for doing the same.

public class MyDynamicModule extends AbstractModule{
  private NeededInterface imp;

  public MyDynamicModule(NeededInterface neededImplimentation){
    this.imp = neededImplimentation;
  }

  @Override
  protected void configure() {
    bind(NeededInterface.class)
          .annotatedWith(Names.named("keyname"))
          .toInstance(neededImplimentation);
    /*.
      .
      .
      .
     *1000s of other binding configuration which are not related to the discussion**/
  }     
}

I know the alternatives, but I need to know if having this piece of code is wrong? If it is, I need to do a major revamp to replace just this one line of code, which in-turn would be a huge overhead for my application.

I needed to find a way to dynamically add a bind-configuration to an existing module. From performance point of view, the above logic seemed simple and straight forward.

Answer 1

这样做很好。您将无法将任何依赖项注入NeededImplementation，但只要您不需要注入任何依赖项就可以了。我想你在启动时有某种条件逻辑，它选择基于某种东西的不同实现？命令行参数？属性文件？您已经拥有执行此决策过程的代码;您应该能够将代码放入Provider<NeededInterface>而不会有太多困难，但您没有提供详细信息。你建议你的构造函数有数百个参数吗？

如果您只有一个实现类，那么您可以这样做：

bind(NeededInterface.class)
      .annotatedWith(Names.named("keyname"))
      .to(NeededImplimentation.class)
      .in(Singleton.class);

如果类有一个无参数构造函数，你会得到相同的结果。你不想让Guice为你创造对象的原因是什么？