Question

I have the following class:

class MySelectBox {
    public MySelectBox(Provider<Map<? extends Object, ? extends Object>> providerArrayIdToLabel) {
        ...
    }
}

And I’m trying to pass this in code that uses this class:

new MySelectBox(new Provider<Map<Long, String>>{
    ... my implementation of Provider ...
});

The compiler gives the following error:

The constructor MySelectBox(new Provider<Map<Long,String>>(){}) is undefined

Why? Why is the method undefined? What should I change in the constructor’s signature to make it accept Provider<Map<Long, String>>

Note: the Provider interface is:

public interface Provider<T> extends javax.inject.Provider<T> {
  T get();
}

Answer 1

Change the declaration of the MySelectBox constructor to this:

public MySelectBox(Provider<? extends Map<? extends Long, ? extends String>> providerArrayIdToLabel)