JwtGrantedAuthoritiesConverter should allow configuring the authorities claim name

[jzheaux]

Related to #6945

It would be nice if an application could indicate a custom claim name for GrantedAuthoritys without creating a custom converter.

Something like:

JwtGrantedAuthoritiesConverter converter = new JwtGrantedAuthoritiesConverter();
converter.setAuthoritiesClaimName("authorities");

Would be easier to do than:

Converter<Jwt, List<GrantedAuthorities>> converter = jwt -> {
    List<String> authorities = (List<String>) jwt.getClaim("authorities");
    return authorities.stream()
        .map(authority -> "SCOPE_" + authority)
        .map(SimpleGrantedAuthority::new)
        .collect(Collectors.toList());
};

So, let's add a setter to JwtGrantedAuthoritiesConverter called setAuthoritiesClaimName so that the converter knows which claim to look for.

[andifalk]

Hi @jzheaux
has anybody already claimed this first timers issue?
Would make sense to implement this one together with #7101. If this is ok for you I would be glad to take over implementation for both.

[jzheaux]

@andifalk, it's yours!