Guice的bind（）中的in（）...是做什么的？

Question

In Guice's documentation, the chapter about Untargetted Bindings presents this example:

bind(AnotherConcreteClass.class).in(Singleton.class);

What does the in() do? The doc doesn't mention what it is for.

Answer 1

It's just the scope I think. It also accept the Scopes enum - either Singleton or NO_SCOPE.

A scope is a level of visibility that instances provided by Guice may have. By default, an instance created by the Injector has no scope, meaning it has no state from the framework's perspective -- the Injector creates it, injects it once into the class that required it, and then immediately forgets it. Associating a scope with a particular binding allows the created instance to be "remembered" and possibly used again for other injections.

http://google-guice.googlecode.com/svn/tags/3.0/javadoc/com/google/inject/Scopes.html#SINGLETON