Guice inject context instance that is created upon each request

Question

Is there a way to have Guice to bind to a certain type of instance that is created upon new request?

Pseudocode using with ThreadLocal:

// upon request incoming, creating the context
Context context = new Context(request, response);
// save to threadlocal so later on we can get it from
// a provider
Context.setThreadLocal(context);
...

// in the AppModule.java file
modules.add(new AbstractModule() {
    @Override   
    protected void configure() {
        bind(Context.class).toProvider(new Provider<Context>() {
            @Override public Context get() {return Context.getThreadLocal();}
        });
    }
});
...

// in another source file
Injector injector = Guice.createInjector(modules);
// suppose Foo has a context property and injector shall
// inject the current context to foo instance
Foo foo = injector.getInstance(Foo.class); 

Can I implement this behavior without a ThreadLocal?

Answer 1

Guice has the concept of Scopes. It sounds like you're looking for something bound with the @RequestScoped annotation. This will bind an instance that persists for the life of the request, and will inject a new object for the next request.

There is also @SessionScoped for when you want the object to persist for an entire session.

You can read up on their examples here, which includes some language on how to use @RequestScoped.