Expose reuseRefreshTokens feature

[Glamdring]

Currently only the validity of the refresh token is exposed for configuration (via ClientDetailsServiceConfigurer), but you can't specify whether to reuse refresh tokens.

Well, you can, with ugly reflection, but it should be prettier:

    endpoints.clientDetailsService(detailsService); //autowired detailsService instance

    // we need this in order to reuse the private createTokenServices() method to properly populate the default values
    Method method = endpoints.getClass().getDeclaredMethod("createTokenServices");
    method.setAccessible(true);
    DefaultTokenServices defaultService = (DefaultTokenServices) ReflectionUtils.invokeMethod(method, endpoints);
    defaultService.setReuseRefreshToken(false);
    endpoints.tokenServices(defaultService);

[dsyer]

You can create your own instanceof DefaultTokenServices and set it up however you want (no need for reflection since it has public constructor and methods). It might be useful to expose that boolean property, but I'm not sure the right way to do it is directly on the AuthorizationServerEndpointsConfigurer. It feels like a builder for the token services might be a better abstraction (if you feel like making a contribution).

[Glamdring]

Reflection is needed because the fields that are set by default in the createTokenServices method require too much extra logic.

when I have time, I may make a PR.

[dsyer]

I guess that's a different definition of "not needed" than I used. Fair enough. A PR would be excellent in any case (please do the contributor's agreement - link in README - if you haven't already).

[jonas-grgt]

I feel like making this contribution if it's ok for @Glamdring

The ideas for the builder I currently have look like this

        @Override
        public void configure(AuthorizationServerEndpointsConfigurer endpoints) throws Exception {
            endpoints
                    .tokenServices(
                            endpoints.tokenServiceConfigurer()
                                .tokenStore(tokenStore)
                                .tokenEnhancer(tokenEnhancer)
                                .reuseRefreshToken(true))
                    .authenticationManager(authenticationManager);

// or separate the builder in a different configurer method (I prefer this approch)

       @Override
        public void configure(TokenServicesConfigurer tokenServices) throws Exception {
                    tokenServices.tokenStore(tokenStore)
                           .tokenEnhancer(tokenEnhancer)
                           .reuseRefreshToken(true)