Guice迭代多个绑定

Question

If I have an interface IBaseFunction and multiple implementations for this interface. How can I iterate over the bindings calling a method on each ie

public class MyModule extends AbstractModule {
  @Override 
  protected void configure() {

bind( IBaseFunction.class).annotatedWith( ExDelete.class).to( ExDeleteFunction.class);
bind( IBaseFunction.class).annotatedWith( ExAdd.class).to( ExAddFunction.class);
...

  }
}

I need to call a function 'publish() on each binding (makes the handler available on a bus)

I could call the function on each binding individually like this :-

ExDeleteFunction functionExDelete = injector.getInstance( ExDeleteFunction.class);
ExDeleteFunction.publish();
ExAddFunction functionExAdd = injector.getInstance( ExAddFunction.class);
ExAddFunction.publish();

However what I would like to do is iterate over these and call the 'publish' function on all of them, is there a way of doing this ? Maybe using injector.getAllBindings() ? Something like this :-

  Injector injector = Guice.createInjector( new ServicesModule() );

  Map<Key<?>, Binding<?>> bindings = injector.getAllBindings();
  for (Binding<?> binding : bindings.values()) {
      Key<?> key = binding.getKey();
...??

or is there a simpler way ?

Answer 1

Yes, there is much simpler way, called Multibindings . With this you will be able to do something like

public class BaseFunctionsModule extends AbstractModule {
    @Override
    public void configure() {
        Multibinder<BaseFunction> multibinder = Multibinder.newSetBinder(binder(), BaseFunction.class);
        mapBinder.addBinding().to(ExDeleteFunction.class);
        mapBinder.addBinding().to(ExAddFunction.class);
        // others
    }
}

public static void main(String[] args) {
    Injector injector = Guice.createInjector(new BaseFunctionsModule());
    Set<BaseFunction> functions = injector.getInstance(new TypeLiteral<Set<BaseFunction>>() {});
    for (BaseFunction function : functions) {
        function.publish();
    }
}

However, in this way it may be not possible to inject your functions separately (I don't know, you need to test it); you may also look into MapBinder .