Does Guice binding bind subclass as well? -

so have module binds interface implementation class.

bind(ilocalstore.class).to(localstore.class); 

will binding inject following constructor:

@inject public localstoreuser(localstore localstore) {     this.localstore = localstore } 

the injection work, not because of binding.

guice treats lookups if simple map<key, provider> lookup, key composed of (binding annotation, parameterized type) pair. guice not automatically walk type hierarchy you, or otherwise modify lookup key (checking non-annotated or raw type binding, instance).

however, if localstore has public no-argument constructor, guice can create type directly, code above work—it has nothing binding subclasses automatically.

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consider following example:

interface {} interface b extends {} public class c implements b {} 

• without bindings @ all, inject c, because has implicit public no-arg constructor. requesting injection of or b fail.

• if bind(a.class).to(c.class) inject (explicit) or c (implicit) not b. guice not bind subinterface well, b has no implementation.

• same goes superclasses/superinterfaces: if bind(b.class).to(c.class) inject b (explicit) or c (implicit) not a, though b extends a.

• if bind(a.class).to(b.class) and bind(b.class).to(c.class), inject a, b, or c without repeating yourself.